Evaluation of Parity in the Federal Employees Health Benefits (FEHB) Program: Final Report. Impact on Access to Care, Service Use, and Cost

12/31/2004

Implementing parity required changing the nominal benefits for coverage of treating mental health and substance abuse (MH/SA) disorders. The dimensions of the nominal benefit that are most often affected when parity policies are implemented are:

  • copayments,
  • deductibles, and
  • limits on covered services (inpatient days and outpatient visits) or expenditures.

In traditional fee-for-service, indemnity-type arrangements, changes in the dimensions of nominal benefits typically result in increases in spending on and utilization of MH/SA care as the MH/SA benefits are expanded (Newhouse et al., 1993; Frank et al., 1986; Manning et al., 1992).

It was expected that in many cases, health plans that contracted with the Office of Personnel Management (OPM) would be implementing changes in the manner in which MH/SA care was managed alongside the changes in nominal benefits associated with the parity policy. Consequently, the ability of the Parity Evaluation Research Team (PERT) to disentangle the separate effects of changes in management from changes in nominal benefits was uneven across health plans and limited in all cases. This is because not all management responses were observable by the PERT. Thus, in most cases, it was possible to estimate only the aggregate “net effect” of implementing parity.

To assess the impact of the parity policy on access, utilization, costs, and quality, the PERT obtained the following from nine selected plans:25

  • two years of claims/encounter data, pre-parity (1999, 2000), and
  • two years of claims/encounter data, post-parity (2001, 2002).

Claims/encounter data for the same four years were also obtained from the Medstat MarketScan® database to form comparison group plans.

Key Research Questions

The analyses in this chapter addressed the following research questions:

  • What are the patterns of access to MH/SA services (where access is operationalized as probability of service use) within select FEHB plans both before and after implementing parity?
  • Do these patterns of access differ by type of user, type of service, level of service, or type of condition? How do these patterns of access compare to secular trends?
  • What are the patterns of service utilization for MH/SA services both before and after the parity policy implementation? How do these patterns compare to secular trends (i.e. general patterns of care outside of the FEHB Program)?
  • Have aggregate, per-enrollee, and per-user spending for MH/SA services changed after the implementation of the parity policy? How do these spending changes compare to secular trends?
  • Have out-of-pocket costs to beneficiaries utilizing MH/SA services (e.g., deductibles, copayments, and out-of-pocket limits) changed after implementation of the parity policy? How do these changes compare to secular trends?
  • How well do patterns of care for MH/SA reflect adherence to quality of care guidelines both before and after the parity policy implementation?

Data Collection

Acquiring Claims Data

For each of the nine selected plans, PERT investigators identified, with the assistance of OPM staff, and established a contact with a designated member of the plan’s data information/claims department.

A PERT member interviewed each plan representative to obtain information on:

  • how the data were structured,
  • what data elements were available, and
  • how the relevant data files could be linked.

PERT investigators worked closely with each representative to identify unique issues with that plan’s data systems before any data were transferred to the PERT.

A preliminary list of variable definitions and names was developed and distributed to each plan to ensure consistency of definitions and completeness. After incorporating any modifications into the list, plans were asked to send electronic claims data in the requested format to the PERT.

Once PERT investigators received the electronic claims data, they conducted a number of quality checks on the data. For example, the proportion of missing values for key variables, such as Current Procedural Terminology (CPT) and diagnosis codes, was tracked. PERT investigators reported to the Government Project Officers (GPOs) and to the rest of the PERT any variables for which the proportion of missing values was higher than standard for the industry and developed a plan for addressing the problem. Trends in claims over time were tracked to identify any unreasonable disruptions in those trends that might signal a problem with data quality.

HMO-W1 provided a mix of claims and encounter data for the general medical services records and only claims data for the MH/SA services. To create estimates of MH/SA spending from the encounter data, investigators applied the average copayment and plan expenditure rates from the MH/SA plan data set to the encounter records. For example, they applied the MH/SA vendor’s average copayment and plan expenditure rates for MH/SA inpatient admissions to each MH/SA inpatient admission occurring in a general medical facility. Similarly, they used the MH/SA vendor’s average copayment and plan expenditure rates per each day of MH/SA outpatient care as an estimate for each day of MH/SA outpatient care occurring in a general medical setting.

PERT cleaned and merged the data (e.g., pharmacy and utilization data). All data were stored on a single machine dedicated to the project, and modifications were documented in a formal log. Data discrepancies were resolved through discussion with the designated plan representative and with PERT members.

The PERT used claims data on MH/SA service use from FEHB enrollees of the selected plans according to the sampling plan shown in Appendix C.

Constructing Analysis Files

Using enrollment and claims/encounter data from each plan contributing such data, PERT staff created a person-level file for these FEHB plan enrollees. This file included:

  • demographics and dates of enrollment from the plan’s enrollment file,
  • MH/SA claims,
  • general medical claims, and
  • pharmacy claims for the individual over the period 1999 to 2002.

Two key issues raised by the construction of data files were:

  • identifying claims for MH/SA services within claims databases, and
  • assigning costs to encounter data (shadow claims) to create spending data.

Identifying MH/SA Services

To examine the effects of the parity policy on MH/SA utilization and spending, PERT researchers specified an algorithm for identifying MH/SA services within claims data, shown in Figure IV-1. Although some types of MH/SA services delivered in certain settings were well coded with appropriate diagnostic information (for example, inpatient MH/SA care for a patient with schizophrenia), claims for many other MH/SA services lacked accurate diagnostic information, particularly when delivered in the primary-care sector. For example, a sizable number of individuals with a claim for an MH/SA medication had no coinciding claim with an MH/SA diagnosis.

For the evaluation, MH/SA utilization and spending includes inpatient and outpatient services associated with specified MH/SA disorders and with use of MH/SA medications.

Figure IV-1. Algorithm to identify use of MH/SA services

Figure IV-1. Algorithm to identify use of MH/SA services

To identify claims for MH/SA services, PERT investigators used algorithms developed from previous analyses of private-sector claims databases and tailored them as needed to fit each plan’s unique data systems. According to these algorithms, a list of specific International Classification of Diseases, 9th Revision Clinical Modification (ICD-9-CM)26 codes associated with MH/SA conditions was first identified. The list of specific ICD9-CM codes contained all codes in the 290 to 319 range except 290, 293, 294, 310, 315, 316, 317, 318, and 319 (including all decimal sub codes), as well as 305.1 (tobacco use disorder) and 305.8 (antidepressant abuse).

Claims were identified as MH/SA inpatient stays if the last hospital primary diagnosis and the majority of the primary diagnoses on the record for an inpatient stay (for room and board, facility, and inpatient institutional charges) were MH/SA conditions.27

For outpatient care, claims were identified as MH/SA if any of these conditions were met:

  • presence of a primary diagnosis of MH/SA,
  • indication that an MH/SA-specific procedure was performed,
  • an indication of a face-to-face encounter or visit with an MH/SA provider,
  • a plan’s coding a service as MH/SA, or
  • indication of an MH/SA-specific place of service.

To identify MH/SA medication use, the PERT developed two lists of medications, both shown in Appendix C, List of Medications for Identifying MH/SA Use and Spending.

  • The restricted list contains medications that are used only for MH/SA conditions.
  • The expanded list contains medications that are used for MH/SA conditions as well as for general medical disorders.

PERT researchers counted all medications on the restricted list as MH/SA medication use/spending, even if no other indication of MH/SA use (inpatient or outpatient) existed. In addition, if the patient had any MH/SA use/spending in the year (i.e., MH/SA inpatient care, MH/SA outpatient, or use of any MH/SA medication on the restricted list), then all medications used by that patient from the expanded list were also counted as MH/SA use/spending.

Limitations of Claims Data

Several limitations are associated with using claims data. Claims data provide an artificial precision about health problems by listing single or only a few diagnoses, when, in reality, multiple problems may exist. Many MH/SA diagnoses are also underreported in claims data, yielding an undercount of MH/SA utilization and cost.

Other than assessing individuals independently from the treating provider, there is no solution to those problems of diagnostic inaccuracy. Finally, claims data provide no information on unmet need for MH/SA treatment, just as they cannot tell us whether the services used were truly needed.

Analytic Methods

The analytical perspective used to assess the impact of parity was to view the change in spending for a given health plan as the result of three main factors:

  • changes in enrollment patterns (numbers of enrollees joining various plans),
  • changes in spending per enrollee, and
  • changes in case mix of enrollees.

Changes in spending per user consist of changes in:

  • the probability of using services (access);
  • the types of services used by users, e.g., the mix of outpatient, inpatient, and prescription medications services (utilization); and
  • the level of spending within each class of services (cost).

Thus, the analytic strategy was designed to study the impact of the parity policy on expenditures by examining changes in aggregate spending and the components of spending separately.

Each of these analyses provided different types of information on the impact of parity. Some analyses examined how parity affected access to treatment in general as well as to specific treatments (e.g., inpatient care, outpatient care, or MH/SA medications). Other analyses focused on the intensity and duration of treatment, as well as on cost, i.e., cost to the plan and cost to the beneficiary (e.g., out-of-pocket spending) of treatment received.

The outcomes of principal interest included the following:

  • Total health care spending per enrollee;
  • Total out-of-pocket spending on all health care per enrollee;
  • MH/SA spending per enrollee;
  • Out-of-pocket MH/SA spending per MH/SA service user;
  • Mental health care spending per mental health (MH) service user;
  • Out-of-pocket MH spending per MH service user;
  • Substance abuse (SA) spending per SA treatment user;
  • Out-of-pocket SA spending per SA treatment user;
  • Probability of any MH/SA service utilization;
  • Probability of any MH service utilization alone;
  • Probability of any SA service utilization alone;
  • Probability of using particular types of MH/SA services (i.e., inpatient or outpatient);
  • Probability of prescription medication treatment for MH/SA (for MH/SA combined and individually);
  • Per-user spending for MH/SA inpatient care, MH/SA outpatient care, and MH/SA prescription medications conditional on use of any of those services (for MH/SA combined and individually); and
  • Intensity of use of particular types of MH/SA services, conditional on using that service (e.g., number of outpatient visits, inpatient days, or psychotropic medication days); intensity of service use will be examined for MH/SA combined and individually.

The evaluation design relied on two basic approaches: a before-after-parity (interrupted time-series) assessment of the impact of the parity policy and a difference-in-differences design.

Before-after-parity Analysis

PERT investigators applied the before-after-parity comparisons to the nine selected FEHB plans. Initial analyses provided basic descriptions of how spending per enrollee in total, for MH/SA combined, and for MH/SA separately changed for all enrollees and for a cohort of continuously enrolled beneficiaries for the period 1999 to 2002. The analysis of continuously enrolled beneficiaries provided some basic descriptions of spending patterns before and after implementing parity, holding constant the enrolled population.

Similar analyses were conducted on continuously enrolled beneficiaries for utilization rates of any MH/SA care, utilization rates of specific MH/SA services (e.g., inpatient and prescription medications), and MH/SA spending per user. The spending analyses were conducted separately for plan spending, for enrollee out-of-pocket payments, and for plan spending plus enrollee out-of-pocket payments. Impacts on out-of-plan use and utilization beyond limits were not estimated directly because of lack of data.

PERT researchers also assessed the impact of parity on spending and utilization patterns using multivariate models to control for changes in the demographic and diagnostic profiles of enrollees (for analyses including all enrollees) and MH/SA users (for analyses limited to the continuously enrolled). These included estimating multipart models (Newhouse et al., 1993).

An additional set of analyses focused on changes in enrollment patterns. These analyses examined the impact of benefit design and management changes on enrollment across plans.

Difference-in-differences Analysis

The difference-in-differences models compared outcomes for selected FEHB plans pre- and post-parity with outcomes over the same time period for matched comparison plans that are not part of the FEHB Program.

The source of data on appropriate comparison plans came from the Medstat MarketScan® database. The Medstat data set included:

  • preferred provider organizations (PPO),
  • point of service plans (POS),
  • health maintenance organizations (HMO), and
  • managed indemnity plans of large employers (often self-insured).

These plans are spread across the nation, although not according to the distribution of the overall population.

Medstat plans were matched to FEHB plans on the following criteria:

  • plan type (HMO versus not HMO),
  • location of enrollees (region), and
  • enrollee demographics.

Figure IV-2 shows the basic structure of the difference-in-differences design. PERT researchers applied this design to the set of outcomes and cohorts described above in the before-after-parity analysis. The estimated impact of the parity policy on a particular outcome was estimated as: (C-A) - (D–B).

Figure IV-2. Difference-in-differences approach

  FEHB Plan Comparison Plan
Pre-parity A B
Post-parity C D

This approach takes into account secular trends that cannot be accounted for by simple before-after-parity comparisons. This methodology was applied in the context of both descriptive and multivariate analyses. The approach permits relatively strong inferences to be made about the policy impact of parity.

A variety of econometric issues arose in the context of these analyses. The first was the use of multipart models. There were issues related to the following:

  • Using the difference-in-differences method in the context of nonlinear models, such as a logit or a nonlinear least-squares model (Mullahy, 1998);
  • Correlation among observed spending or observed use data due to the repeated observations from each enrollee;
  • Transforming conditional utilization and spending outcomes; and
  • Reconstructing net impacts on spending.

Because the difference-in-differences approach requires estimating a coefficient for an interaction term, the net impact of the parity policy on an outcome, e.g., the probability of using MH/SA care, could not be calculated in a straightforward fashion. Instead, PERT investigators calculated the average impact of the probability of MH/SA service use, i.e., (C-A) – (D-B), using simulation methods based on the estimated equations for the case when the appropriate dummy variables are set to one and zero.

PERT investigators adopted a generalized linear model for characterizing the relationship between spending and the impact of parity. Several “link” functions and distributional assumptions were examined to model expected spending. These included poisson models with log links, gamma models with log links, and normal models with identity links. After checking models, the PERT researchers used a normal model to characterize spending. The investigators accounted for correlation among repeated observations for an enrollee using standard statistical procedures. Simulation methods were used to construct difference-in-differences estimates of the overall spending impacts of parity from multipart econometric models and included estimated standard errors of the estimates.

Indicators of case mix were used as a dependent variable to study possible selection effects stemming from parity and also as covariates in multivariate models of utilization and spending for MH/SA care. In models using the continuously enrolled, the diagnostic indicators were used as statistical covariates in the conditional (on any MH/SA use) spending and utilization models. Because the focus is on the continuously enrolled, these analyses were not driven by plan selection effects. Thus, diagnoses were treated as independent covariates not influenced by the introduction of parity. (For analyses using all enrollees to study utilization and spending, the diagnoses of enrollees within a plan may be affected by the introduction of parity through plan selection effects.)

Findings on Access to Care, Service Use, and Cost -- All Enrolled Beneficiaries (FEHB Plans)

Overview

In this section, we present an overview of the findings on all enrolled beneficiaries from the nine selected FEHB plans. We provide a synopsis of each plan’s demographic composition and findings on the basic structure of MH/SA care utilization and spending.

The findings presented in this section are meant to provide background on the data rather than form the basis for inferences about the impact of the FEHB parity policy. For the latter, we focus solely on the continuously enrolled population.

Given the dynamic nature of enrollment in these FEHB plans, in which members join and exit yearly, using all enrollees -- rather than only the continuously enrolled -- to analyze the impact of the parity policy would greatly complicate attempts to control for the composition of the beneficiaries in the FEHB plan population over the four evaluation years (1999 through 2002).

This is particularly the case when using claims data that offer only a limited set of descriptors on demographic characteristics of enrollees (i.e., age, gender, and relationship to the health plan policy holder).

Therefore, we use a sample of continuously enrolled beneficiaries to rigorously estimate impacts of the parity policy. By adopting such a strategy, we study the effects of the policy change on a stable population, thereby eliminating population change (i.e., selection effects) as an influence on observed patterns of utilization and spending on MH/SA services. Thus, while a focus on the continuously enrolled population limits the generalizability of the results, it strengthens the inferences we can make about the estimated policy impacts.

Findings from the continuously enrolled beneficiary population are presented in the next section, titled Findings on Access to Care, Service Use, and Cost -- Continuously Enrolled Beneficiaries (FEHB and Comparison Plans). The remainder of this section presents findings on all enrollees.

Plan Population Characteristics

Tables IV.A.1 through IV.A.9 report population size and characteristics of enrollees for each of the nine selected FEHB plans, i.e., gender, age, and relation to the health plan policy holder. These tables show that each of the nine plans, except FFS-NAT and HMO-NE, experienced population growth during the 1999 to 2002 period.

In contrast, the populations of FFS-NAT and HMO-NE steadily declined over the four years.

Table IV.A.1. FFS-NAT--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 714,449 643,708 601,059 557,272
Female 52.5% 52.7% 52.7% 52.8%
17 years of age and younger 2.9% 2.8% 2.7% 2.6%
18-25 14.1% 13.7% 13.5% 13.2%
26-35 7.3% 6.2% 5.7% 5.1%
36-45 22.6% 20.9% 19.4% 18.0%
46-55 33.5% 34.8% 35.8% 36.9%
56-65 19.6% 21.5% 22.9% 24.2%
Employee 49.6% 49.8% 50.1% 50.3%
Spouse 32.7% 32.8% 33.0% 33.3%
Child/other dependent 17.6% 17.4% 16.9% 16.5%

 

Table IV.A.2. FFS-MA1--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 186,438 189,830 191,019 196,503
Female 54.7% 54.8% 55.0% 55.0%
17 years of age and younger 1.8% 1.8% 1.7% 1.7%
18-25 9.1% 9.1% 9.2% 9.5%
26-35 11.7% 11.4% 11.1% 11.4%
36-45 21.3% 20.9% 20.2% 19.9%
46-55 32.4% 32.3% 32.6% 31.5%
56-65 23.7% 24.6% 25.2% 26.0%
Employee 61.5% 61.4% 61.7% 62.2%
Spouse 29.2% 29.3% 29.1% 28.6%
Child/other dependent 9.4% 9.4% 9.3% 9.2%

 

Table IV.A.3. FFS-MA2--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 124,942 129,796 132,220 138,289
Female 52.6% 52.7% 52.8% 52.7%
17 years of age and younger 2.4% 2.3% 2.3% 2.3%
18-25 10.6% 10.6% 10.7% 10.7%
26-35 10.3% 9.6% 9.0% 9.2%
36-45 23.1% 22.9% 22.3% 22.0%
46-55 31.4% 31.7% 32.0% 31.2%
56-65 22.2% 23.0% 23.8% 24.5%
Employee 51.7% 51.8% 52.2% 52.6%
Spouse 36.0% 36.1% 35.7% 35.5%
Child/other dependent 12.3% 12.2% 12.1% 11.9%

 

Table IV.A.4. FFS-NE1--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 64,343 66,245 67,603 72,242
Female 50.8% 50.9% 51.0% 50.8%
17 years of age and younger 2.4% 2.5% 2.6% 2.5%
18-25 10.7% 10.7% 11.1% 11.3%
26-35 13.9% 13.0% 12.0% 11.8%
36-45 28.6% 28.1% 27.4% 26.5%
46-55 28.4% 29.3% 30.4% 30.6%
56-65 16.0% 16.4% 16.6% 17.3%
Employee 54.4% 54.2% 53.9% 54.2%
Spouse 33.8% 33.9% 33.7% 33.4%
Child/other dependent 11.9% 12.0% 12.4% 12.4%

 

Table IV.A.5. FFS-NE2--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 37,613 39,157 40,725 42,828
Female 50.3% 50.4% 50.5% 50.5%
17 years of age and younger 2.2% 2.1% 2.2% 2.2%
18-25 9.7% 9.8% 9.9% 10.3%
26-35 16.5% 15.8% 15.1% 15.1%
36-45 26.9% 26.0% 25.2% 24.3%
46-55 29.2% 30.4% 31.4% 31.2%
56-65 15.5% 15.9% 16.2% 17.0%
Employee 58.3% 58.0% 57.9% 57.7%
Spouse 31.5% 31.6% 31.4% 31.5%
Child/other dependent 10.2% 10.5% 10.7% 10.8%

 

Table IV.A.6. FFS-W--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 92,697 95,568 96,383 101,097
Female 51.6% 51.6% 51.6% 51.3%
17 years of age and younger 2.2% 2.2% 2.1% 2.2%
18-25 9.8% 9.7% 10.0% 10.2%
26-35 12.2% 11.6% 11.2% 11.6%
36-45 24.6% 24.0% 23.5% 22.9%
46-55 29.7% 30.2% 30.7% 30.3%
56-65 21.6% 22.2% 22.4% 22.9%
Employee 55.5% 55.5% 55.7% 56.2%
Spouse 33.3% 33.3% 33.0% 32.7%
Child/other dependent 11.2% 11.2% 11.3% 11.1%

 

Table IV.A.7. FFS-S--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 122,601 132,692 139,126 148,726
Female 52.7% 52.6% 52.5% 52.3%
17 years of age and younger 2.7% 2.6% 2.7% 2.6%
18-25 12.0% 11.9% 12.0% 12.2%
26-35 13.7% 13.9% 13.9% 14.8%
36-45 23.0% 22.8% 22.4% 22.2%
46-55 27.7% 28.0% 28.5% 27.7%
56-65 20.9% 20.8% 20.6% 20.6%
Employee 51.0% 51.3% 51.5% 52.2%
Spouse 35.7% 35.5% 35.2% 34.7%
Child/other dependent 13.3% 13.2% 13.3% 13.1%

 

Table IV.A.8. HMO-W1--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 37,035 35,224 38,579 44,127
Female 50.6% 50.9% 51.2% 51.2%
17 years of age and younger 2.8% 2.8% 2.7% 2.7%
18-25 12.0% 12.0% 12.4% 12.6%
26-35 19.5% 17.4% 16.3% 16.0%
36-45 30.7% 30.7% 30.9% 30.8%
46-55 25.1% 26.3% 27.2% 27.6%
56-65 10.0% 10.9% 10.6% 10.4%
Employee 58.3% 57.6% 57.0% 56.9%
Spouse 28.9% 29.7% 30.1% 30.3%
Child/other dependent 12.8% 12.7% 13.0% 12.8%

 

Table IV.A.9. HMO-NE--All Enrolled Beneficiaries by Age and Beneficiary Status

  1999 2000 2001 2002
N 59,405 51,826 48,794 44,290
Female 52.4 52.3 52.3 52.1
17 years of age and younger 2.7 2.8 2.6 2.6
18-25 13.0 12.8 12.5 11.9
26-35 15.6 13.7 11.6 9.9
36-45 28.6 28.5 27.8 27.0
46-55 28.3 30.5 32.3 34.0
56-65 11.8 11.6 13.3 14.5
Employee 59.8 59.4 59.4 59.9
Spouse 26.6 26.6 26.3 26.0
Child/other dependent 13.5 14.2 14.3 14.1

Probability of Any MH/SA, MH, and SA Use

Table IV.A.10 presents the probability of any MH/SA use for each of the nine selected plans. Comparing 1999 to 2002 reveals considerable heterogeneity in trends with respect to the probability of MH/SA service use (this may also be termed the treated prevalence rate). In all nine plans, though, the probability of MH/SA use increased from pre- to post-parity.

FFS-NAT experienced a 21.4% increase in probability of MH/SA use from the pre-parity 1999 period to the post-parity 2002 period, which was the largest increase of the nine plans. However, FFS-NAT also had the lowest initial (1999) probability of MH/SA use of the nine plans, 11.7%.

Finally, HMO-NE had the smallest change from pre- to post-parity in probability of MH/SA use, an increase of 4.7% from 1999 to 2002. Pre- to post-parity percent change information is provided for both 1999 to 2002 and 2000 to 2002 to illustrate early as well as later changes in the pre-parity period.

Table IV.A.10. Plan Probability of MH/SA Use

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT 11.7% 12.5% 13.9% 14.2% 21.4% 13.6%
FFS-MA1 16.8% 17.6% 18.3% 18.5% 10.1% 5.1%
FFS-MA2 16.7% 17.6% 18.9% 19.7% 18.0% 11.9%
FFS-NE1 13.0% 14.4% 15.1% 15.5% 19.2% 7.6%
FFS-NE2 12.3% 13.3% 14.1% 14.0% 13.8% 5.3%
FFS-W 13.8% 15.2% 15.8% 16.6% 20.3% 9.2%
FFS-S 15.0% 16.0% 16.9% 17.4% 16.0% 8.7%
HMO-W1 13.6% 14.5% 14.8% 14.7% 8.1% 1.4%
HMO-NE 15.0% 14.9% 15.0% 15.7% 4.7% 5.4%

Table IV.A.11 presents the probability of any MH service use for the nine plans, which closely tracked the overall MH/SA use rates.

Table IV.A.11. Plan Probability of MH Use

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT 11.5% 12.3% 13.8% 14.2% 23.5% 15.4%
FFS-MA1 16.6% 17.5% 18.1% 18.4% 10.8% 5.1%
FFS-MA2 16.6% 17.5% 18.7% 19.5% 17.5% 11.4%
FFS-NE1 12.8% 14.2% 14.9% 15.4% 20.3% 8.5%
FFS-NE2 12.2% 13.1% 13.9% 13.8% 13.1% 5.3%
FFS-W 13.7% 15.1% 15.7% 16.5% 20.4% 9.3%
FFS-S 14.9% 15.9% 16.8% 17.3% 16.1% 8.8%
HMO-W1 13.5% 14.3% 14.6% 14.5% 7.4% 1.4%
HMO-NE 13.7% 13.5% 13.6% 14.2% 3.6% 5.2%

Table IV.A.12 presents the probability of any SA service use for the nine plans. Pre-parity SA service use ranged from 0.4% to 0.6% for all plans except HMO-NE, which had pre-parity SA service rates of 2.0% in 1999 and 2.1% in 2000. Post-parity SA service use ranged from 0.5% to 0.8% for all plans except (again) HMO-NE, which had post-parity SA service rates of 2.0% in 2001 and 2.3% in 2002.

For eight of the nine plans, the probability of SA service use increased from pre- to post-parity. FFS-NAT, however, maintained a 0.5% SA service use rate across all four years both pre- and post-parity. FFS-NE 2 experienced a 25% increase in SA service use from pre-parity 1999 to post-parity 2002, but no change from 2000 to 2002.

Across the nine plans, the change from pre- to post-parity in rates of SA service use ranged from 0.0% to 40%, with most plans in the 20% to 40% use range.

Table IV.A.12. Plan Probability of SA Use

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT 0.5% 0.5% 0.5% 0.5% 0.0% 0.0%
FFS-MA1 0.6% 0.6% 0.6% 0.7% 16.7% 16.7%
FFS-MA2 0.6% 0.6% 0.7% 0.8% 33.3% 33.3%
FFS-NE1 0.5% 0.6% 0.6% 0.7% 40.0% 16.7%
FFS-NE2 0.4% 0.5% 0.6% 0.5% 25.0% 0.0%
FFS-W 0.5% 0.5% 0.6% 0.6% 20.0% 20.0%
FFS-S 0.5% 0.5% 0.6% 0.7% 40.0% 40.0%
HMO-W1 0.5% 0.5% 0.7% 0.7% 40.0% 40.0%
HMO-NE 20.% 2.1% 2.0% 2.3% 15.0% 9.5%

Inpatient MH/SA, MH, and SA Use

Table IV.A.13 shows the rates of inpatient MH/SA utilization for all nine plans. These rates were generally low, from 1.2% to 2.5%. For most of the nine plans, inpatient utilization rates remained fairly constant or declined over the 1999 to 2002 period. This was the case whether the pre-parity basis for comparison was 1999 or 2000. One exception was HMO-W1, which experienced a 58.3% increase in the MH/SA inpatient utilization rate from 2000 to 2002. (NB: Percent change does not reflect the magnitude of use.)

Table IV.A.13. Plan Probability of MH/SA Inpatient Use

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT 2.5% 2.4% 2.1% 2.0% -20.0% -16.7%
FFS-MA1 1.6% 1.6% 1.5% 1.4% -12.5% -12.5%
FFS-MA2 1.6% 1.6% 1.5% 1.4% -12.5% -12.5%
FFS-NE1 2.0% 1.6% 1.9% 1.8% -10.0% 12.5%
FFS-NE2 2.1% 2.0% 2.1% 1.9% -9.5% -5.0%
FFS-W 1.6% 1.4% 1.6% 1.4% -12.5% 0.0%
FFS-S 1.4% 1.7% 1.7% 1.7% 21.4% 0.0%
HMO-W1 1.6% 1.2% 2.0% 1.9% 18.8% 58.3%
HMO-NE 3.4% 3.6% 2.8% 3.1% -8.8% -13.9%

As shown in Table IV.A.14, the inpatient MH service use rate closely tracked the overall MH/SA inpatient results.

Table IV.A.14. Plan Probability of MH Inpatient Use

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT 2.1% 2.1% 2.1% 2.0% -4.8% -4.8%
FFS-MA1 1.3% 1.4% 1.3% 1.2% -7.7% -14.3%
FFS-MA2 1.4% 1.4% 1.2% 1.2% -14.3% -14.3%
FFS-NE1 1.4% 1.2% 1.3% 1.2% -14.3% 0.0%
FFS-NE2 1.7% 1.6% 1.4% 1.4% -17.6% -12.5%
FFS-W 1.3% 1.2% 1.2% 1.0% -23.1% -16.7%
FFS-S 1.2% 1.4% 1.3% 1.3% 8.3% -7.1%
HMO-W1 1.3% 0.9% 1.4% 1.4% 7.7% 55.6%
HMO-NE 2.0% 2.2% 1.7% 2.0% 0.0% -9.1%

Inpatient SA service use rates and trends, presented in Table IV.A.15, varied considerably across plans. Six of the nine plans experienced an increase in inpatient SA service use, with 1999 to 2002 pre- to post-parity increases ranging from about 17% (FFS-NE1) to 150% (FFS-S), and 2000 to 2002 increases ranging from 20% (FFS-NE2) to 250% (HMO-W1).

FFS-MA1 experienced no change in inpatient SA service use across any of the years from 1999 to 2002. Two plans, FFS-NAT and HMO-NE, had decreases in inpatient SA use, about 25% and 13% from 2000 to 2002, respectively. These plans also had the highest initial inpatient SA service use rates, 0.9% for FFS-NAT and 1.6% for HMO-NE.

Table IV.A.15. Plan Probability of SA Inpatient Use

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT 0.9% 0.8% 0.7% 0.6% -33.3% -25.0%
FFS-MA1 0.3% 0.3% 0.3% 0.3% 0.0% 0.0%
FFS-MA2 0.3% 0.2% 0.3% 0.3% 0.0% 50.0%
FFS-NE1 0.6% 0.5% 0.7% 0.7% 16.7% 40.0%
FFS-NE2 0.4% 0.5% 0.8% 0.6% 50.0% 20.0%
FFS-W 0.4% 0.2% 0.5% 0.4% 0.0% 100.0%
FFS-S 0.2% 0.3% 0.5% 0.5% 150.0% 66.7%
HMO-W1 0.3% 0.2% 0.7% 0.7% 133.3% 250.%
HMO-NE 1.6% 1.5% 1.2% 1.3% -18.8% -13.3%

MH/SA and SA Spending Per Enrollee

Table IV.A.16 reports total MH/SA spending (plan plus out-of-pocket spending) per enrollee per year for the nine FEHB plans. FFS-NAT experienced a 37.6% increase from pre- to post-parity in per enrollee MH/SA spending for the 1999 to 2002 period.

FFS-NAT’s growth in per enrollee MH/SA spending for the 2000 to 2002 period was 21.9%. FFS-NAT had the highest spending growth rate among the PPO or POS plans (all plans excluding HMO-W1 and HMO-NE). The Association plans (all plans excluding HMO-W1, HMO-NE, and FFS-NAT) experienced spending growth rates of 8.3% to 30.2% for the 1999 to 2002 period.

Table IV.A.16. Total MH/SA Spending Per Enrolleea

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $85 $96 $105 $117 37.6% 21.9%
FFS-MA1 $213 $235 $258 $241 13.1% 2.6%
FFS-MA2 $139 $154 $176 $181 30.2% 17.5%
FFS-NE1 $123 $133 $157 $160 30.1% 20.3%
FFS-NE2 $180 $190 $195 $195 8.3% 2.6%
FFS-W $13 $145 $167 $171 28.6% 17.9%
FFS-S $138 $151 $138 $143 3.6% -5.3%
HMO-W1 $98 $104 $124 $136 38.8% 30.8%
HMO-NE $126 $137 $140 $157 24.6% 14.6%
  1. Total MH/SA spending includes inpatient and outpatient services and medications and is defined as the sum of out-of-pocket payments and insurance payments.

The two HMO plans, HMO-W1 and HMO-NE, showed somewhat different patterns. Using 1999 as the base year, total MH/SA spending per enrollee increased 39% for HMO-W1. This is the highest rate of growth in per enrollee MH/SA spending of all the nine plans.

For HMO-NE, the growth from pre- to post-parity in per enrollee MH/SA spending using 1999 as the base year was 24.6%. When 2000 is used as the base year, HMO-NE spending per enrollee increased 14.6% from pre- to post-parity.

Table IV.A.17 reports total SA service spending per enrollee for all nine plans. For seven of the nine plans, total SA service spending increased over the pre- to post-parity periods. FFS-NAT SA service spending did not change from pre- to post-parity. This plan, however, also had the second highest initial SA spending rates, $9 per enrollee in both 1999 and 2000. HMO-NE, which experienced only a 14.3% spending increase from 1999 to 2002 and no change from 2000 to 2002, had the highest initial SA spending rates, $14 in 1999 and $16 in 2000 per enrollee.

HMO-W1 had the lowest initial SA spending rate, $2 per enrollee in both 1999 and 2000, as well as the largest spending increase per enrollee from pre- to post-parity, 450%.

In no plan did SA spending per enrollee decline.

Table IV.A.17. Total SA Spending Per Enrolleea

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $9 $9 $8 $9 0.0% 0.0%
FFS-MA1 $6 $6 $7 $9 50.0% 50.0%
FFS-MA2 $5 $4 $5 $6 20.0% 50.0%
FFS-NE1 $8 $9 $11 $12 50.0% 33.3%
FFS-NE2 $9 $8 $13 $13 44.4% 62.5%
FFS-W $6 $4 $7 $9 50.0% 125.0%
FFS-S $6 $8 $7 $8 33.3% 0.0%
HMO-W1 $2 $2 $9 $11 450.0% 450.0%
HMO-NE $14 $16 $14 $16 14.3% 0.0%
  1. Total SA spending includes inpatient and outpatient services and medications and is defined as the sum of out-of-pocket payments and insurance payments.

MH/SA and SA Spending Per User

Table IV.A.18 shows total MH/SA spending per user for all nine plans. Spending patterns varied widely across plans. Six plans showed increased MH/SA spending per user from pre- to post-parity, ranging from about 2% to 29%. HMO-W1 showed the largest increase from pre- to post-parity, 29.2% over the 1999 to 2002 period and 26.1% over the 2000 to 2002 period. This plan also had the smallest initial per user spending rate, $647 in 1999 and $663 in 2000.

Table IV.A.18. Total MH/SA Spending Per Usera

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $671 $707 $713 $755 12.5% 6.8%
FFS-MA1 $1,225 $1,289 $1,349 $1,252 2.2% -2.9%
FFS-MA2 $801 $844 $897 $884 10.4% 4.7%
FFS-NE1 $907 $896 $988 $973 7.3% 8.6%
FFS-NE2 $1,390 $1,380 $1,308 $1,306 -6.0% -5.4%
FFS-W $923 $920 $1,010 $970 5.1% 5.4%
FFS-S $875 $901 $776 $766 -12.5% -15.0%
HMO-W1 $647 $663 $777 $836 29.2% 26.1%
HMO-NE $836 $916 $936 $1,005 20.2% 9.7%
  1. Total MH/SA spending includes inpatient and outpatient services and medications and is defined as the sum of out-of-pocket payments and insurance payments.

Two plans had decreases in MH/SA spending per user from pre- to post-parity, FFS-NE2 and FFS-S. FFS-NE2 showed a decline in spending of 6.0% from 1999 to 2002 and 5.4% from 2000 to 2002; it also had the highest initial spending rates, $1,390 in 1999 and $1,380 in 2000.

MH/SA spending per user for FFS-S decreased the most of all the nine plans, 12.5% from 1999 to 2000 and 15.0% from 2000 to 2002. FFS-S’s initial spending rates were about average for the nine plans.

FFS-MA1, which had the second highest initial MH/SA spending rates per user, $1,225 in 1999 and $1,289 in 2000, showed a small spending increase of 2.2% from 1999 to 2002, and a small spending decrease of 2.9% from 2000 to 2002.

Table IV.A.19 shows total per user SA service spending for all nine plans. Again, findings revealed wide variations in spending rates and patterns across plans. Six plans saw clear increases in per user SA service spending, one plan (FFS-NAT) experienced a spending decrease, and two plans (FFS-S and HMO-NE) had mixed results.

Table IV.A.19. Total SA Spending Per Usera

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $74 $68 $53 $58 -21.6% -14.7%
FFS-MA1 $37 $33 $37 $46 24.3% 39.4%
FFS-MA2 $28 $23 $26 $30 7.1% 30.4%
FFS-NE1 $58 $58 $69 $75 29.3% 29.3%
FFS-NE2 $73 $58 $86 $90 23.3% 55.2%
FFS-W $39 $24 $44 $52 33.3% 116.7%
FFS-S $39 $46 $41 $44 12.8% -4.3%
HMO-W1 $16 $13 $56 $70 337.5% 438.5%
HMO-NE $90 $107 $95 $102 13.3% -4.7%
  1. Total SA spending includes inpatient and outpatient services and medications and is defined as the sum of out-of-pocket payments and insurance payments.

Among plans showing increases in per user SA spending, HMO-W1 had the largest spending increases from pre- to post-parity by far, about 338% from 1999 to 2002 and 439% from 2000 to 2002. However, HMO-W1 also had the lowest initial per user SA spending rates by far, $16 in 1999 and $13 in 2000. In contrast, pre-parity spending rates for the other eight plans ranged from $28 to $90 in 1999 and from $23 to $107 in 2000. Most spending increases were in the range of 23% to 55%.

FFS-NAT, which had the second highest initial per user SA spending rate, $74 in 1999 and $68 in 2000, was the only plan to post clear decreases in SA service spending from pre- to post-parity, 21.6% from 1999 to 2000 and 14.7% from 2000 to 2002.

HMO-NE, which had the highest initial per user SA spending rates, $90 in 1999 and $107 in 2000, showed an increase of 13.3% from 1999 but a decrease of 4.7% from 2000 to 2002.

MH/SA Medication Spending

Per enrollee total spending on MH/SA medications results are shown in Table IV.A.20. These results generally track those for per user total MH/SA spending, shown in Table IV.A.21 and discussed below.

Table IV.A.20. Total MH/SA Medication Spending Per Enrolleea

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $34 $41 $51 $58 70.6% 41.5%
FFS-MA1 $90 $105 $119 $122 35.6% 16.2%
FFS-MA2 $78 $91 $105 $109 39.7% 19.8%
FFS-NE1 $51 $61 $73 $78 52.9% 27.9%
FFS-NE2 $54 $63 $73 $76 40.7% 20.6%
FFS-W $65 $78 $86 $91 40.0% 16.7%
FFS-S $64 $75 $86 $90 40.6% 20.0%
HMO-W1 $54 $60 $62 $64 18.5% 6.7%
HMO-NE $50 $56 $61 $68 36.0% 21.4%
  1. Total MH/SA medication spending is defined as the sum of out-of-pocket payments and insurance payments.

 

Table IV.A.21. Total MH/SA Medication Spending per Usera

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $266 $306 $345 $377 41.7% 23.2%
FFS-MA1 $519 $575 $624 $632 21.8% 9.9%
FFS-MA2 $448 $500 $537 $533 19.0% 6.6%
FFS-NE1 $372 $409 $462 $475 27.7% 16.1%
FFS-NE2 $417 $460 $488 $508 21.8% 10.4%
FFS-W $450 $496 $521 $516 14.7% 4.0%
FFS-S $403 $444 $484 $480 19.1% 8.1%
HMO-W1 $357 $381 $385 $395 10.6% 3.7%
HMO-NE $336 $374 $410 $433 28.9% 15.8%
  1. Total MH/SA medication spending is defined as the sum of out-of-pocket payments and insurance payments.

All nine plans experienced increases from pre- to post-parity in per user MH/SA medication spending, as illustrated in Table IV.A.21. FFS-NAT, which had the lowest level of per-user pre-parity MH/SA medication for both 1999 ($266) and 2000 ($306), also had the largest medication spending increases, 41.7% from 1999 to 2002 and 23.2% from 2000 to 2002. HMO-W1 posted the smallest pre- to post-parity increase in medication spending, 10.6% from 1999 to 2000 and 3.7% from 2000 to 2002. HMO-W1 had the third lowest level of pre-parity mediation spending, $357 in 1999 and $381 in 2000. In each of the plans, medication spending increases were greater for the 1999 to 2002 period than for the 2000 to 2002 period.

Out-of-pocket MH/SA and SA Spending Per Enrollee

As shown in Table IV.A.22, per enrollee MH/SA out-of-pocket spending rates and trends varied widely across plans and plan years. These data on out-of-pocket spending are important as an indicator of the degree of insurance provided in the plan. Out-of-pocket spending amounts may increase if overall spending increases even when larger proportion of charges for services are covered by insurance. In general, plans with the lowest initial MH/SA out-of-pocket spending rates experienced the highest out-of-pocket spending increases, while plans with the highest initial out-of-pocket spending rates experienced decreases or no change in this spending.

Table IV.A.22. MH/SA Out-of-pocket Spending Per Enrolleea

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $31 $35 $37 $41 32.3% 17.1%
FFS-MA1 $60 $66 $61 $60 0.0% -9.1%
FFS-MA2 $36 $40 $35 $38 5.6% -5.0%
FFS-NE1 $33 $36 $34 $36 9.1% 0.0%
FFS-NE2 $52 $55 $48 $48 -7.7% -12.7%
FFS-W $36 $38 $33 $36 0.0% -5.3%
FFS-S $39 $42 $26 $31 -20.5% -26.2%
HMO-W1 $9 $10 $15 $15 66.7% 50.0%
HMO-NE $14 $17 $18 $26 85.7% 52.9%
  1. Total out-of-pocket spending includes inpatient and outpatient services and medications.

HMO-NE and HMO-W1 showed the largest pre- to post-parity increases in MH/SA out-of-pocket spending. HMO-NE MH/SA out-of-pocket spending increased 85.7% from 1999 to 2002 and 52.9% from 2000 to 2002. HMO-W1 MH/SA per enrollee out-of-pocket spending increased 66.7% from 1999 to 2002 and 50.0% from 2000 to 2002. These two plans also had the lowest initial per enrollee out-of-pocket spending rates, $9 in 1999 and $10 in 2000 for HMO-W1, and $14 in 1999 and $17 in 2000 for HMO-NE. By contrast, the other seven plans had pre-parity per enrollee out-of-pocket spending rates of $31 to $66.

Table IV.A.23 shows per enrollee out-of-pocket spending for SA services. Overall, the per enrollee SA service out-of-pocket spending rates had a fairly limited range. Thus, their interpretation is of limited value.

Table IV.A.23. SA Out-of-pocket Spending Per Enrolleea

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $2 $2 $1 $2 0.0% 0.0%
FFS-MA1 $2 $2 $1 $1 -50.0% -50.0%
FFS-MA2 $2 $1 $1 $1 -50.0% 0.0%
FFS-NE1 $2 $3 $2 $2 0.0% -33.3%
FFS-NE2 $3 $2 $2 $2 -33.3% 0.0%
FFS-W $1 $1 $1 $1 0.0% 0.0%
FFS-S $2 $2 $1 $1 -50.0% -50.0%
HMO-W1 $0 $0 $0 $0 0.0% 0.0%
HMO-NE $0 $0 $0 $0 0.0% 0.0%
  1. Total out-of-pocket spending includes inpatient and outpatient services and medications.

Out-of-pocket MH/SA and SA Spending Per User

Table IV.A.24 shows MH/SA out-of-pocket spending per user, an indicator of insurance protection for users of MH/SA care. It is important to note that this indicator has a complex interpretation since out-of-pocket burden per service can decrease while total out-of-pocket spending can increase if the amount of service use increases sufficiently.

Table IV.A.24. MH/SA Out-of-pocket Spending Per Usera

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $246 $257 $252 $264 7.3% 2.7%
FFS-MA1 $346 $361 $318 $309 -10.7% -14.4%
FFS-MA2 $208 $218 $177 $188 -9.6% -13.8%
FFS-NE1 $246 $246 $216 $217 -11.8% -11.8%
FFS-NE2 $403 $402 $321 $319 -20.8% -20.6%
FFS-W $249 $243 $197 $202 -18.9% -16.9%
FFS-S $245 $252 $148 $164 -33.1% -34.9%
HMO-W1 $60 $64 $95 $95 58.3% 48.4%
HMO-NE $91 $112 $117 $169 85.7% 50.9%
  1. Total out-of-pocket spending includes inpatient and outpatient services and medications.

Once again, plans with the lowest initial spending levels generally showed the largest increases in spending from pre- to post-parity, while plans with the highest spending levels generally showed decreases or only small increases in these spending rates.

Three of the nine plans (FFS-NAT, HMO-W1, and HMO-NE) experienced increases in MH/SA out-of-pocket-spending per user over the 1999 to 2002 period. The percentage increases ranged from about 3% (FFS-NAT) to 51% (HMO-NE) from 2000 to 2002. All the Association plans experienced declines in out-of-pocket spending per user.

Table IV.A.25 shows per user SA service out-of-pocket spending. Seven of the nine plans experienced substantial decreases in per user SA service out-of-pocket spending, ranging from about 25% to 50%. Only HMO-W1 had a clear increase in this spending, which was 200%. This plan also had the lowest initial SA out-of-pocket spending, $1 in 1999 and 0 in 2000.

In contrast, the other plans had initial per user SA out-of-pocket spending of $9 to $20 in 1999 and $6 to $17 in 2000. However, HMO-NE, which had the second lowest initial SA out-of-pocket spending, $2 in 1999 and $6 in 2000, showed a 50% increase in out-of-pocket spending from 1999 to 2002, but a 50% decrease from 2000 to 2002.

Table IV.A.25. SA Out-of-pocket Spending Per Usera

Plan 1999 2000 2001 2002 Change from pre- to post-parity
1999 to 2002 2000 to 2002
FFS-NAT $18 $17 $8 $12 -33.3% -29.4%
FFS-MA1 $10 $9 $6 $6 -40.0% -33.3%
FFS-MA2 $9 $6 $4 $4 -55.6% -33.3%
FFS-NE1 $16 $17 $12 $12 -25.0% -29.4%
FFS-NE2 $20 $15 $11 $11 -45.0% -26.7%
FFS-W $9 $7 $4 $4 -55.6% -42.9%
FFS-S $10 $14 $6 $6 -40.0% -57.1%
HMO-W1 $1 $0 $1 $3 200.0% N/A
HMO-NE $2 $6 $2 $3 50.0% -50.0%
  1. Total out-of-pocket spending includes inpatient and outpatient services and medications.

Findings on Access to Care, Service Use, and Cost -- Continuously Enrolled Beneficiaries (FEHB and Comparison Plans)

This section reports on both before-after-parity and difference-in-differences analyses of the impact of the parity policy on access (i.e., probability of use), utilization, and costs (i.e., expenditures) in terms of the following:

  • Adult MH/SA care use and spending
  • Adult substance abuse (SA) care use and spending
  • Adult mental health (MH) care use and spending (difference-in-differences analysis only)
  • Adult out-of-pocket spending on MH/SA care
  • Child MH/SA care use and spending
  •  Adult high utilizers of MH/SA care (before-after-parity analysis only)

The results of these analyses are presented in the sections that follow.

Adult MH/SA Use and Spending: Before-after-parity Analysis

Overview and Model

The before-after-parity analysis of utilization and spending was conducted using two-part models that estimated:

  1. probability of MH/SA service use, and
  2. spending for those who used these services.

We analyzed each of the nine FEHB plans separately, focusing on a cohort of continuously enrolled health plan members for the period from 1999 to 2002. The years 1999 and 2000 represented the pre-parity period, while 2001 and 2002 represented the post-parity period.

In the first part of the two-part model, the impact of the parity policy on the probability that an individual used MH/SA services was estimated using a logit regression model. In those regressions, we adjusted for demographic characteristics of the individual (age and gender) and the individual’s relationship to the policyholder (i.e., dependent child or spouse). The age variable also served to adjust for any time trend.

The key variable of interest was an indicator (or dummy) variable that took a value of one for the post-parity period and zero for the pre-parity period. Based on these regressions, we obtained an estimate of the change in the likelihood of using any MH/SA services that was attributable to movement from pre- to post-parity.

However, it is impossible to separate the parity effect from the secular time trend using this analysis approach. Our analysis took into account the repeated measures feature of the data set in calculating the standard error by using a bootstrap estimator to construct 95% confidence intervals for our final estimates (Efron & Tibshriani, 1998).

The second part of the two-part model consisted of an analysis of individual spending on MH/SA services, conditional on using any MH/SA services, employing a least squares regression approach. In this model, we adjusted for individual demographic characteristics and the diagnosis for which an individual received treatment.

As in the logit regression, a before-after-parity indicator variable was the covariate of interest in this model. The coefficient for this variable allowed us to calculate the change in spending that included the presumed effects of the parity policy as well as the secular time trend. Using a bootstrapping technique, we estimated the standard errors for the conditional spending change that account for the repeated measurement design.

Applying the Model

Table IV.B.0 summarizes the change from the pre-parity to the post-parity period in the probability of using any MH/SA services and conditional spending on MH/SA care for the nine FEHB plans identified in Column 1.

Table IV.B.0. Summary Across Plans for Adult MH/SA Use and Spending -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4 Column 5
Absolute percentage point change from pre- to post-parity in the probability of MH/SA use Percentage change from pre- to post-parity in probability of MH/SA use Change from pre- to post-parity in MH/SA spending conditional on any MH/SA usea Percentage change from pre- to post-parity in MH/SA spending conditional on any MH/SA use
Plan Estimate Significance   Estimate Significance  
1. FFS-NAT 2.39% p<0.05 17.02% $40.10 p<0.05 6.80%
2. FFS-MA1 1.63% p<0.05 8.71% $87.43 p<0.05 8.70%
3. FFS-MA2 3.00% p<0.05 16.19% $120.57 p<0.05 19.15%
4. FFS-NE1 2.49% p<0.05 16.54% $125.49 p<0.05 18.10%
5. FFS-NE2 1.86% p<0.05 12.91% $11.99 NS 1.06%
6. FFS-W 2.23% p<0.05 13.83% $135.37 p<0.05 18.59%
7. FFS-S 2.75% p<0.05 15.63% -$45.32 p<0.05 -6.44%
8. HMO-W1 2.64% p<0.05 16.53% $238.85 p<0.05 46.87%
9.  HMO-NE 0.51% p<0.05 3.23% $118.01 p<0.05 17.83%
  1. NS indicates not significant at p<0.05.

Column 2 of Table IV.B.0 reports the absolute percentage point change from pre- to post-parity in the average expected probability of MH/SA service use attributable to parity for each of the nine health plans. Column 3 shows the percent change represented by the estimate of absolute change in probability of use in Column 2 as a percent of the pre-parity probability of use. Column 4 reports the change in conditional MH/SA spending (i.e., conditional on using any MH/SA care). Column 5 shows the percentage change in conditional MH/SA spending based on the results reported in Column 4.

The first stage models generally did not fit the data very well. This occurred, in large part, because the only explanatory variables in the model predicting MH/SA care use were age, gender, and relationship to the health insurance contract holder. These variables have been shown in other research to be weak predictors of MH/SA utilization (Ettner et al, 1997). Thus, the model generally differentiated poorly between users and non-users of MH/SA services. The estimated impact of parity was obtained in this context.

Tables IV.B.1 through IV.B.9 provide details on the absolute utilization and spending patterns for each plan, impact estimates, and standard errors of the impact estimates. Generally, the impacts on the probability of use attributable to parity were estimated with a high level of precision, as indicated by the relatively narrow confidence intervals reported for the impact estimates and shown in Tables IV.B.1 through IV.B.9. Table IV.B.1 provides detailed results for the FFS-NAT analysis, which is summarized in Row 1 of Table IV.B.0. Table IV.B.2 provides detailed results from the FFS-MA1 plan analysis, summarized in Row 2 of Table IV.B.0, and so forth for each of the nine plans. In order to illustrate how the summary findings in Table IV.B.0 were obtained, we examine the results for the FFS-NAT plan in detail.

Panel 1 of Table IV.B.1 reports the descriptive statistics for the actual probability of using MH/SA services (Row 1), actual MH/SA spending per enrollee (Row 2), and actual spending per user of MH/SA services (Row 3) for those continuously enrolled in the FFS-NAT plan. As Row 2 of Table IV.B.1 shows, over the 1999 to 2002 time period, nominal per enrollee spending on MH/SA grew from $83 to $120 in this plan, a 44.6% increase.

In Panel 2 of Table IV.B.1, Row 4 reports the expected probability of using any MH/SA services by year as predicted by the model; Row 5 of Panel 2 reports the average pre- and post-parity expected probability of using any MH/SA services.

Comparing Row 4 with Row 1 of Table IV.B.1 shows the actual versus predicted probabilities of MH/SA use. Thus, for the year 1999, the predicted probability of MH/SA use for FFS-NAT was 14.00%, and the actual rate of use was 13.6%. The 95% confidence intervals around the yearly estimates of the probability of any MH/SA use are quite narrow.

Table IV.B.1. FFS-NAT Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 13.6% 14.5% 16.0% 16.8% 23.5%
2 Actual MH/SA spending per enrollee $83 $93 $107 $120 44.6%
3 Actual MH/SA spending per user $611 $663 $670 $715 17.0%
P
A
N
E
L

2

4 Expected probability of MH/SA use 14.00%
(13.74%, 14.26%)
14.07%
(13.81%, 14.33%)
16.40%
(16.12%, 16.69%)
16.45%
(16.17%, 16.75%)
 
5 Average expected probability of MH/SA use pre- and post-parity 14.04%
(13.77%, 14.29%)
16.42%
(16.14%, 16.72%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 2.39%
(2.16%, 2.61%)
17.02%
7 Expected MH/SA spending per user $596.36
($554.94, $638.18)
$583.76
($540.82, $626.24)
$635.37
($599.57, $671.08)
$624.94
($592.44, $659.57)
8 Average expected pre- and post-parity MH/SA spending per user $590.06
($549.95, $631.42)
$630.16
($598.13, $663.57)
9 Expected change from pre- to post-parity in MH/SA spending per user $40.10
($4.56, $77.67)
6.80%

Panel 3 reports the estimation results for conditional MH/SA spending in the FFS-NAT plan. The expected spending per user based on the regression model is reported in Row 7. The 95% confidence interval for per user MH/SA spending is reported in the parentheses below the point estimate. Thus, in the year 1999, predicted spending in the FFS-NAT plan was $596.36 with a 95% confidence interval of $554.94 to $638.18 (Row 7).

Row 6 of Panel 3 of Table IV.B.1 reports the estimated change from pre- to post-parity in the probability of MH/SA use for the FFS-NAT as 2.39 percentage points with a 95% confidence interval of 2.16% to 2.61%, indicating the change was significantly different from zero. This 2.39 percentage point increase in the probability of MH/SA use is also shown in Column 2 of Row 1 in Table IV.B.0. Row 6 also shows that this 2.39 percentage point change equates to a 17.02% increase from pre- to post-parity in the probability of any MH/SA use for FFS-NAT, which was obtained by dividing the 2.39 percentage point estimate by the 14.04% pre-parity average probability of MH/SA use. The 17.02% increase is also reported in Column 3 of Row 1 of Table IV.B.0.

Comparing this estimate to the Row 3 figure of $611 for actual MH/SA spending per user in 1999 shows the difference between the model’s prediction and the actual level of conditional MH/SA spending. In this case, the actual level of spending was within the 95% confidence interval for the predicted level of 1999 spending. This is not always the case, such as in the prediction of year 2000 conditional MH/SA spending. The implication is that our model generally under predicts actual spending by about 2% to 13% for the FFS-NAT plan.

Panel 3, Row 8 reports the pre- and-post-parity average predicted MH/SA spending per user and their 95% confidence intervals. Thus, in the FFS-NAT, pre-parity spending was $590.06 and post-parity it was $630.16.

Panel 3, Row 9 shows the estimated change in spending from pre- to post-parity as $40.10 for this plan. The relatively large 95% confidence interval ranges from $4.56 to $77.67. This indicates that the estimated parity effect of $40.10 is significantly different from zero at the 5% probability level, where zero means “no change.” We infer the significant difference because the 95% confidence interval does not include zero. The $40.10 estimated parity effect on conditional MH/SA spending also appears in Column 4 of Row 1 of Table IV.B.0. Dividing $40.10 by the pre-parity conditional MH/SA spending estimate of $590.06 yields the percentage change in spending from pre- to post-parity, 6.80%, as reported in Row 9 of Table IV.B.1 and in Column 5 of Row 1 of Table IV.B.0.

Findings Across Plans

Table IV.B.0 summarizes the overall pre- to post-parity estimation results for adult MH/SA service utilization and conditional MH/SA spending for the nine selected FEHB plans. All the estimates of change from pre- to post-parity in the probability of any MH/SA use and conditional spending were significantly different from zero at least at the 5% probability level, except for FFS-NE2’s conditional MH/SA spending increase of $11.99. Examination of the detailed plan results for FFS-NE2 (Table IV.B.5) shows that zero is contained in the 95% confidence interval around the $11.99 pre- to post-parity change estimate.

As shown in Column 2 of Table IV.B.0, the probability of any MH/SA use increased from pre- to post-parity for all nine FEHB plans. HMO-NE had the smallest absolute change in the probability of use, 0.51 percentage points, which represented a 3.23% increase in the rate of any MH/SA use. FFS-MA2 had the largest absolute increase in the probability of any MH/SA use, 3.00 percentage points, which represented a 16.19% increase in the rate of any MH/SA use. However, the FFS-NAT had the largest change in the rate of MH/SA use, an increase of 17.02%. Thus, with the exception of HMO-NE, the rates of change from pre- to post-parity in MH/SA use were in the range of 8.5% to 17.1%.

The absolute changes in conditional MH/SA spending by plan are reported in Column 4 of Table IV.B.0. The estimated changes in absolute spending ranged from a decrease of $45.32 for FFS-S to an increase of $238.85 for HMO-W1. The percentage changes in conditional MH/SA spending are reported in Column 5 of Table IV.B.0 and they also reflect heterogeneity in conditional spending across plans. The FFS-S plan saw a 6.44% decline in conditional MH/SA spending, while the HMO-W1 plan experienced a 46.87% increase.

Discussion

The large increase in adult conditional MH/SA spending reported for HMO-W1 makes this plan very different from the other eight plans. For six of the nine plans, conditional MH/SA spending increases were in the range 6.8% to 18.6%; for four of the nine plans, conditional MH/SA spending increases were in the 17% to 20% range. Thus, the HMO-W1’s increase in conditional spending of 47% is more than twice that found in most of the other eight FEHB plans.

Our impression from the site visit to HMO-W1 is that it implemented substantial fee increases to providers in 2001. We investigated this further in the archival data by examining the price per visit for psychotherapy and found a modest increase that was initiated in 2001. The increase amounted to about $9 per visit or a 5% increase. Thus, it was not sufficient to explain the dramatic rise in HMO-W1’s per-user conditional MH/SA spending.

The number of visits for MH/SA service users of psychotherapy in HMO-W1 increased from an average of 5.7 visits in 1999 to 7 visits in 2002, a change of 22.8%. Finally, spending on psychotropic medications per users grew by 28.5% over the four-year period in this plan. Thus, several factors appear to have contributed to HMO-W1’s large conditional MH/SA spending increases.

Table IV.B.2. FFS-MA1 Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 18.3% 19.1% 20.1% 20.6% 12.6%
2 Actual MH/SA spending per enrollee $214 $235 $262 $249 16.4%
3 Actual MH/SA spending per user $1,168 $1,231 $1,302 $1,211 3.7%
P
A
N
E
L

2

4 Expected probability of MH/SA use 18.67%
(18.32%, 19.03%)
18.75%
(18.40%, 19.13%)
20.32%
(19.98%, 20.68%)
20.36%
(20.01%, 20.72%)
 
5 Average expected probability of MH/SA use pre- and post-parity 18.71%
(18.36%, 19.07%)
20.34%
(20.00%, 20.69%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 1.63%
(1.37%, 1.87%)
8.70%
7 Expected MH/SA spending per user $,1014.35
($966.05, $1059.66)
$994.51
($947.42, $1036.21)
$1,109.24
($1060.26, $1154.55)
$1,074.48
($1030, $1120.25)
8 Average expected pre- and post-parity MH/SA spending per user $1,004.43
($959.01, $1050.15)
$1,091.86
($1046.25, $1137.52)
9 Expected change from pre- to post-parity in MH/SA spending per user $87.43
($51.18, $124.43)
8.71%

 

Table IV.B.3. FFS-MA2 Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 18.1% 19.0% 20.9% 22.1% 22.1%
2 Actual MH/SA spending per enrollee $132 $147 $176 $186 40.9%
3 Actual MH/SA spending per user $730 $773 $842 $840 15.1%
P
A
N
E
L

2

4 Expected probability of MH/SA use 18.46%
(18.14%, 18.82%)
18.60%
(18.28%, 19.97%)
21.47%
(21.11%, 21.86%)
21.59%
(21.23%, 21.98%)
 
5 Average expected probability of MH/SA use pre- and post-parity 18.53%
(18.21%, 18.90%)
21.50%
(21.17%, 21.92%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 3.00%
(2.72%, 3.30%)
16.19%
7 Expected MH/SA spending per user $629.24
($589.10, $674.22)
$629.79
($590.74, $677.01)
$753.91
($717.43, $791.77)
$746.25
($709.43, $781.78)
8 Average expected pre- and post-parity MH/SA spending per user $629.51
($589.82, $677.42)
$750.08
($713.91, $786.09)
9 Expected change from pre- to post-parity in MH/SA spending per user $120.57
($79.99, $153.19)
19.15%

 

Table IV.B.4. FFS-NE1 Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 14.3% 15.8% 17.0% 18.1% 26.6%
2 Actual MH/SA spending per enrollee $116 $131 $156 $163 40.5%
3 Actual MH/SA spending per user $814 $830 $919 $903 10.9%
P
A
N
E
L

2

4 Expected probability of MH/SA use 14.98%
(14.65%, 15.28%)
15.12%
(14.78%, 15.42%)
17.48%
(17.14%, 17.82%)
17.60%
(17.25%, 17.96%)
 
5 Average expected probability of MH/SA use pre- and post-parity 15.05%
(14.71%, 15.35%)
17.54%
(17.20%, 17.89%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 2.49%
(2.23%, 2.77%)
16.54%
7 Expected MH/SA spending per user $695.34
($659.10, $732.46)
$691.23
($653.06, $726.38)
$822.64
($779.48, $870.18)
$814.90
($774.11, $861.02)
8 Average expected pre- and post-parity MH/SA spending per user $693.28
($657.29, $728.31)
$818.77
($776.66, $865.08)
9 Expected change from pre- to post-parity in MH/SA spending per user $125.49
($87.57, $165.08)
18.10%

 

Table IV.B.5. FFS-NE2 Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 14.0% 14.9% 16.1% 16.5% 17.9%
2 Actual MH/SA spending per enrollee $180 $195 $204 $214 18.9%
3 Actual MH/SA spending per user $1,290 $1,314 $1,269 $1,300 0.8%
P
A
N
E
L

2

4 Expected probability of MH/SA use 14.34%
(13.90%, 14.84%)
14.48%
(14.06%, 14.98%)
16.22%
(15.74%, 16.70%)
16.33%
(15.85%, 16.83%)
 
5 Average expected probability of MH/SA use pre- and post-parity 14.41%
(13.98%, 14.91%)
16.27%
(15.80%, 16.77%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 1.86%
(1.48%, 2.20%)
12.91%
7 Expected MH/SA spending per user $1,153.70
($1,074.94, $1,240.75)
$1,114.04
($1,037.31, $1,196.92)
$1,165.95
($1,082.48, $1,254.15)
$1,125.77
($1,046.49, $1,208.53)
8 Average expected pre- and post-parity MH/SA spending per user $1,133.87
($1,056.58, $1,218.59)
$1,145.86
($1,066.17, $1,230.03)
9 Expected change from pre- to post-parity in MH/SA spending per user $11.99a
($-76.14, $98.20)
1.06%
  1. Not significant at p<0.05.

 

Table IV.B.6. FFS-W Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 15.5% 16.8% 17.9% 18.8% 21.3%
2 Actual MH/SA spending per enrollee $136 $145 $176 $183 34.6%
3 Actual MH/SA spending per user $881 $867 $981 $971 10.2%
P
A
N
E
L

2

4 Expected probability of MH/SA use 16.00%
(15.73%, 16.25%)
16.24%
(15.97%, 16.51%)
18.22%
(17.92%, 18.55%)
18.46%
(18.17%, 18.78%)
 
5 Average expected probability of MH/SA use pre- and post-parity 16.12%
(15.85%, 16.38%)
18.34%
(18.04%, 18.66%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 2.23%
(1.98%, 2.47%)
13.83%
7 Expected MH/SA spending per user $741.16
($695.98, $785.72)
$714.97
($672.70, $763.63)
$867.56
($829.00, $908.31)
$859.30
($821.48, $897.29)
8 Average expected pre- and post-parity MH/SA spending per user $728.06
($685.85, $772.31)
$863.43
($825.46, $898.75)
9 Expected change from pre- to post-parity in MH/SA spending per user $135.37
($94.62, $176.61)
18.59%

 

Table IV.B.7. FFS-S Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 17.0% 18.2% 19.7% 21.0% 23.5%
2 Actual MH/SA spending per enrollee $131 $147 $143 $156 19.1%
3 Actual MH/SA spending per user $768 $814 $726 $742 -3.4%
P
A
N
E
L

2

4 Expected probability of MH/SA use 17.46%
(17.17%, 17.76%)
17.73%
(17.44%, 18.02%)
20.22%
(19.89%, 20.56%)
20.46%
(20.13%, 20.81%)
 
5 Average expected probability of MH/SA use pre- and post-parity 17.59%
(17.30%, 17.89%)
20.34%
(20.01%, 20.68%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 2.75%
(2.50%, 2.98%)
15.63%
7 Expected MH/SA spending per user $711.49
($670.28, $756.52)
$695.41
(654.77, $741.02)
$659.62
($629.32, $692.77)
$656.63
($626.73, $687.91)
8 Average expected pre- and post-parity MH/SA spending per user $703.45
($661.10, $747.70)
$658.12
($628.30, $689.20)
9 Expected change from pre- to post-parity in MH/SA spending per user -$45.32
(-$85.00, -$6.52)
-6.44%

 

Table IV.B.8. HMO-W1 Adult MH/SA Use and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 15.6% 16.5% 18.1% 19.2% 23.1%
2 Actual MH/SA spending per enrollee $101 $113 $147 $168 66.3%
3 Actual MH/SA spending per user $647 $688 $814 $875 35.2%
P
A
N
E
L

2

4 Expected probability of MH/SA use 15.83%
(15.37%, 16.29%)
16.11%
(15.64%, 16.66%)
18.46%
(18.01%, 18.96%)
18.76%
(18.29%, 19.26%)
 
5 Average expected probability of MH/SA use pre- and post-parity 15.97%
(15.50%, 16.44%)
18.61%
(18.14%, 19.10%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 2.64%
(2.21%, 3.04%)
16.53%
7 Expected MH/SA spending per user $489.41
($431.23, $542.11)
$529.76
($470.39, $585.52)
$739.26
($671.90, $808.32)
$757.60
($680.86, $825.85)
8 Average expected pre- and post-parity MH/SA spending per user $509.59
($451.33, $561.74)
$748.43
($671.94, $815.44)
9 Expected change from pre- to post-parity in MH/SA spending per user $238.85
($172.42, $313.49)
46.87%

 

Table IV.B.9. HMO-NE Adult MH/SA Using and Spending -- Before-after-parity Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 15.6% 15.9% 16.0% 16.6% 6.4%
2 Actual MH/SA spending per enrollee $131 $139 $151 $169 29.0%
3 Actual MH/SA spending per user $839 $876 $947 $1,019 21.5%
P
A
N
E
L

2

4 Expected probability of MH/SA use 15.67%
(15.40%, 15.96%)
15.90%
(15.63%, 16.48%)
16.20%
(15.93%, 16.48%)
16.39%
(16.10%, 16.67%)
 
5 Average expected probability of MH/SA use pre- and post-parity 15.78%
(15.51%, 16.07%)
16.30%
(16.01%, 16.58%)
P
A
N
E
L

3

6 Absolute change from pre- to post-parity in the expected probability of MH/SA use 0.51%
(0.21%, 0.82%)
3.23%
7 Expected MH/SA spending per user $650.10
($600.86, $701.29)
$673.89
($625.67, $724.89)
$760.17
($708.00, $812.32)
$799.84
($745.22, $857.55)
8 Average expected pre- and post-parity MH/SA spending per user $661.99
($616.47, $709.54)
$780.00
($728.48, $833.42)
9 Expected change from pre- to post-parity in MH/SA spending per user $118.01
($57.98, $177.74)
17.83%

Adult MH/SA Use and Spending: Difference-in-differences Analysis

Overview and Model

We compared the before-after-parity-analysis data on MH/SA use and conditional spending reported in the previous section with data from a matched comparison group plan. For each of the nine selected FEHB plans, we constructed a comparison group using administrative data from the Medstat MarketScan® database. Enrollees were matched on the basis of:

  • health plan type (PPO and POS versus HMO),
  • region of the country, and
  • enrollee demographics.

For FFS-NAT, a national health plan, we matched enrollees in each of the plan’s regions with PPO and POS enrollees of Medstat plans from those same regions, thereby creating a national matched comparison data set.

The difference-in-differences estimates were constructed somewhat differently for the probability of using MH/SA care and for the MH/SA spending for users of that care. In both cases, regression models were estimated. For the probability of MH/SA use model, a logistic regression was estimated that included the following explanatory variables:

  • age (in years),
  • gender,
  • relation to the health insurance plan contract holder,
  • a dummy variable that took a value of one if a beneficiary was in an FEHB plan and zero otherwise,
  • a dummy variable that took a value of one if an observation occurred in the post-parity period (2001, 2002), and
  • the interaction of the two dummy variables.

Because the logistic regression was a non-linear model, we used the coefficients in the model to predict the expected MH/SA utilization rates for the study population in each year according to pre- and post-parity and FEHB versus comparison plan status. We then calculated the difference-in-differences estimate for the population and constructed 95% confidence intervals using a bootstrapping procedure.

For the conditional spending regressions, we constructed generalized estimated equations that included the following explanatory variables:

  • age,
  • gender,
  • relation to the health insurance plan contract holder,
  • diagnosis,
  • a pre- and post-parity dummy variable,
  • an FEHB plan control dummy variable, and
  • the interaction of the two dummy variables.

The coefficient for the interaction terms in this model was the difference-in-differences estimate for MH/SA spending conditional on MH/SA use. The 95% confidence interval was constructed from the estimated standard errors from the regression models. In both parts of the model, we adjusted for “repeated” measures by allowing correlation between observations for a beneficiary in estimating the regression coefficients.

Applying the Model

Table IV.C.0 summarizes the difference-in-differences analysis results for all nine FEHB plans. Column 2 of Table IV.C.0 reports the difference-in-differences estimates for the effect of parity on the probability of MH/SA service use. Column 3 reports the difference-in-differences estimates for the effect of parity on MH/SA spending conditional on MH/SA use. The statistical significance of each estimate is also shown in these columns.

Table IV.C.0. Summary Across Plans for Adult MH/SA Use and Spending -- Difference-in-differences Analysis

Column 1 Column 2 Column 3
Difference-in-differences in probability of MH/SA use from pre- to post-paritya Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity
Plan Estimate Significance Estimate Significance
FFS-NAT -0.12% NS -$68.97 p<0.05
FFS-MA1 -0.94% p<0.05 -$42.13 NS
FFS-MA2 0.78% p<0.05 $27.11 NS
FFS-NE1 0.23% NS -$5.50 NS
FFS-NE2 -0.38% NS -$119.26 p<0.05
FFS-W -0.24% NS -$22.60 NS
FFS-S 0.35% NS -$201.99 p<0.05
HMO-W1 0.31% NS $32.96 NS
HMO-NE -2.73% p<0.05 -$77.82 p<0.05
  1. NS indicates not significant at p<0.05.

Table IV.C.0 was constructed from the plan-specific Tables IV.C.1 through IV.C.9, each of which shows the expected pre- and post-parity probability of MH/SA service use28 and the difference-in-differences estimates of MH/SA use and conditional spending when the FEHB plans are matched with their respective Medstat comparison plans. To illustrate the links between Tables IV.C.1 through IV.C.9 and the difference-in-differences analysis summary results in Table IV.C.0, we again turn to the findings for FFS-NAT, which are shown in Table IV.C.1 and summarized in Row 1 of Table IV.C.0.

Panel 1 of Table IV.C.1 contains six rows representing three pairs of descriptive results for the FFS-NAT plan and its Medstat comparison group. Rows 1 and 2 of Panel 1 show the actual probability of any MH/SA use for FFS-NAT adults and its matched comparison plan, respectively. Likewise, Rows 3 and 4 show actual MH/SA spending per enrollee and Rows 5 and 6 show actual MH/SA spending per user of these services for FFS-NAT and its comparison plan, respectively.

For example, examination of Row 5 of Panel 1 of Table IV.C.1 indicates that actual MH/SA spending per user in FFS-NAT increased from $611 in 1999 (pre-parity) to $715 in 2002 (post-parity), a 17.0% spending increase. Row 6 shows that for FFS-NAT’s matched comparison plan, spending also increased, from $905 in 1999 to $1,065 in 2002, a similar 17.7% spending increase.

Table IV.C.1. FFS-NAT Adult MH/SA Use and Spending -- Difference -in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 13.6% 14.5% 16.0% 16.8% 23.5%
2 Comparison plan actual probability of MH/SA use 20.2% 21.0% 22.3% 23.8% 17.8%
3 Actual MH/SA spending per enrollee $83 $93 $107 $120 44.6%
4 Comparison plan actual MH/SA spending per enrollee $182 $204 $234 $252 38.5%
5 Actual MH/SA spending per user $611 $663 $670 $715 17.0%
6 Comparison plan acutal MH/SA spending per user $905 $972 $1,051 $1,065 17.7%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 13.97%
(13.47%, 14.40%)
16.32%
(15.89%, 16.76%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 20.26%
(19.74%, 20.79%)
22.72%
(22.22%, 23.19%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.21%a
(-0.66%, 0.44%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$68.97
(-$89.02, -$48.92)
  1. Not significant at p<0.05.

Panel 2 of Table IV.C.1 contains the average expected rates of MH/SA use, expressed as estimated percentages of the continuously enrolled adult population that uses MH/SA services. Row 7 shows that for the FFS-NAT plan in the pre-parity period, 14.0% of adults were estimated to use MH/SA services, whereas 16.3% were estimated to use MH/SA services in the post-parity period. Row 8 shows that for the FFS-NAT matched comparison population, the corresponding percentages were 20.3% in the pre-parity period and 22.7% in the post-parity period.

Panel 3 shows the difference-in-differences estimate in the probability of MH/SA use from pre- to post-parity for FFS-NAT as -0.21 percentage points. This estimate, which also appears in Column 2 of Row 1 of summary Table IV.C.0, was calculated by the formula (C-A) – (D-B) shown previously in Figure IV-2.

The estimated 95% confidence interval for the -0.21 percentage-point estimate was –0.66 to 0.44. Because this confidence interval contains zero, the –0.21 estimated impact of parity on adult MH/SA service use was not significantly different from zero at the 5% probability level. That is, the probability of adult use of MH/SA services did not differ between the pre- and post-parity periods when trends in non-FEHB plans (i.e., the Medstat matched comparison plan) were taken into account.

Panel 4 reports the difference-in-differences estimate of adult MH/SA spending conditional on MH/SA use from pre- to post-parity. For FFS-NAT and its comparison plan, the estimated impact of parity on spending was a decrease of $68.97, with a 95% confidence interval ranging from –$89.02 to –$48.92. Thus, the parity spending impact estimate was significantly different from zero at the 5% probability level, i.e., adult MH/SA spending for users of MH/SA services differed between the pre- and post-parity periods when trends in matched non-FEHB plans were taken into account.

From the previously reported implementation analysis (see chapter III for details), recall that for the FFS-NAT plan the implementation of parity coincided with the introduction of a managed behavioral health care carve-out program. Thus, the FFS-NAT difference-in-differences estimate of MH/SA conditional spending captures the impact of both the new managed care arrangement and the parity policy.

Findings Across Plans

Table IV.C.0 summarizes the difference-in-differences use and spending estimates for adults in the nine selected FEHB plans and their comparators. As shown in Column 2 of Table IV.C.0, a positive and significant effect of parity on the probability of any MH/SA use was observed only for the FFS-MA2 plan, for which a 0.78% increase in use relative to its matched comparison plan was estimated.

For the remaining eight plans, the estimated impact of parity on the probability of any MH/SA use was either positive but not significantly different from zero, or was significant but negative (e.g., the significant and large 2.73% relative decrease in MH/SA use for HMO-NE).

Thus, while the before-after use and spending analysis found an increase in the rate of MH/SA services use when comparing the 1999 to 2000 time period with the 2001 to 2002 period, the difference-in-differences analysis indicated that the observed post-parity increase in MH/SA use was primarily due to a general trend in increased MH/SA service utilization over the same time period.

Column 3 of Table IV.C.0 reports the difference-in-differences estimates for MH/SA spending conditional on MH/SA service use. For four plans, significant decreases in spending attributable to parity were estimated. The FFS-NAT, FFS-NE2, FFS-S, and HMO-NE plans all had spending impact estimates that were negative and significantly different from zero at a 5% probability level. The magnitude of these estimates ranged from -$68.97 for FFS-NAT to -$201.99 for FFS-S. As noted above, the FFS-NAT plan introduced a behavioral health carve-out program at the same time the parity policy was implemented, whereas FFS-NE2, HMO-NE, and FFS-S already had managed behavioral health care initiatives in place before the implementation.

As Column 3 of Table IV.C.0 shows, the other spending impact estimates were rather modest, ranging from -$42.13 to $32.96, and did not differ significantly from zero. Therefore, the estimates for the impact of parity on MH/SA spending conditional on MH/SA use offered no evidence of significant increases in spending attributable to the parity policy. To the contrary, the impact estimates offer evidence that for four FEHB plans, FEHB spending increases from pre- to post-parity were significantly smaller than the spending increases experienced by the comparison plans.

Discussion

The plan-specific Tables IV.C.1 through IV.C.9 generally show growth in the FEHB plans’ MH/SA spending per user over the four years observed, with only FFS-S experiencing an actual decline in MH/SA spending. However, spending also grew in the comparison plans over the same time period. The difference-in-differences results confirm that MH/SA spending growth in the selected FEHB plans was on par with or below that in other large, privately insured populations.

These results are “negative” in terms of the impact of the parity policy in that few significant differences were found in the probability of adult MH/SA service use or expenditures and almost none of the increases that some critics of parity had predicted were evident.

These findings raise an interpretation issue, i.e., Was there really limited impact of the parity policy on MH/SA utilization and spending, or did the evaluation design lack the necessary power to detect an impact? Several factors lead us to believe the former:

  • First, the descriptive data reported earlier in Panel 1 of Tables IV.C.1 through IV.C.9 aligned well with the analysis results in that any observed differences between FEHB plan enrollees and comparison plan enrollees were relatively small in magnitude.
  • Second, the sample sizes used in the analysis were large and have been sufficient to show significant impacts for similar policy measures (e.g., the impact of carve-out programs).
  • Finally, the qualitative research (in the site visit component of the evaluation) was generally consistent with the view that the parity policy had only a modest impact on MH/SA service use and spending.

Thus, for all these reasons, we conclude that the estimates reported here reflect the underlying phenomena associated with the implementation of parity, rather than a statistical artifact.

Table IV.C.2. FFS-MA1 Adult MH/SA Use and Spending -- Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 18.3% 19.1% 20.1% 20.6% 12.6%
2 Comparison plan actual probability of MH/SA use 16.6% 17.9% 18.8% 20.0% 20.5%
3 Actual MH/SA spending per enrollee $214 $235 $262 $249 16.4%
4 Comparison plan actual MH/SA spending per enrollee $149 $177 $197 $219 47.0%
5 Actual MH/SA spending per user $1,168 $1,231 $1,302 $1,211 3.7%
6 Comparison plan acutal MH/SA spending per user $897 $990 $1,049 $1,093 21.9%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 18.83%
(18.36%, 19.36%)
20.07%
(19.59%, 20.60%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 17.29%
(16.79%, 17.72%)
19.47%
(19.02%, 19.99%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.96%
(-1.46%, -0.38%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$42.13a
(-$126.30, $42.00)
  1. Not significant at p<0.05.

 

Table IV.C.3. FFS-MA2 Adult MH/SA Use and Spending-Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 18.1% 19.0% 20.9% 22.1% 22.1%
2 Comparison plan actual probability of MH/SA use 16.6% 17.9% 18.8% 20.0% 20.5%
3 Actual MH/SA spending per enrollee $132 $147 $176 $186 40.9%
4 Comparison plan actual MH/SA spending per enrollee $149 $177 $197 $219 47.0%
5 Actual MH/SA spending per user $730 $773 $842 $840 15.1%
6 Comparison plan acutal MH/SA spending per user $897 $990 $1,049 $1,093 21.9%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 18.59%
(18.00%, 19.21%)
21.58%
(21.00%, 22.14%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 17.25%
(16.73%, 17.77%)
19.46%
(18.93%, 19.98%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity 0.78%
(0.20%, 1.39%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity $27.11a
($-111.00, $56.70)
  1. Not significant at p<0.05.

 

Table IV.C.4. FFS-NE1 Adult MH/SA Use and Spending-Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 14.3% 15.8% 17.0% 18.1% 26.6%
2 Comparison plan actual probability of MH/SA use 16.6% 17.9% 18.8% 20.0% 20.5%
3 Actual MH/SA spending per enrollee $116 $131 $156 $163 40.5%
4 Comparison plan actual MH/SA spending per enrollee $149 $177 $197 $219 47.0%
5 Actual MH/SA spending per user $814 $830 $919 $903 10.9%
6 Comparison plan acutal MH/SA spending per user $897 $990 $1,049 $1,093 21.9%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 15.06%
(14.65%, 15.49%)
17.50%
(17.05%, 17.99%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 17.27%
(16.79%, 17.72%)
19.47%
(19.02%, 19.99%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.54%a
(-0.31%, 0.74%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$5.50a
(-$96.20, $85.20)
  1. Not significant at p<0.05.

 

Table IV.C.5. FFS-NE2 Adult MH/SA Use and Spending -- Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 14.0% 14.9% 16.1% 16.5% 17.9%
2 Comparison plan actual probability of MH/SA use 16.6% 17.9% 18.8% 20.0% 20.5%
3 Actual MH/SA spending per enrollee $180 $195 $204 $214 18.9%
4 Comparison plan actual MH/SA spending per enrollee $149 $177 $197 $219 47.0%
5 Actual MH/SA spending per user $1,290 $1,314 $1,269 $1,300 0.8%
6 Comparison plan acutal MH/SA spending per user $897 $990 $1,049 $1,093 21.9%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 14.43%
(14.01%, 14.89%
16.25%
(15.81%, 16.75%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 17.26%
(16.84%, 17.72%)
19.46%
(18.99%, 20.00%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.38%a
(-0.89%, 0.23%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$119.26
(-$234.50, -$4.10)
  1. Not significant at p<0.05.

 

Table IV.C.6. FFS-W Adult MH/SA Use and Spending -- Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 15.5% 16.8% 17.9% 18.8% 21.3%
2 Comparison plan actual probability of MH/SA use 17.5% 18.6% 19.8% 21.0% 20.0%
3 Actual MH/SA spending per enrollee $136 $145 $176 $183 34.6%
4 Comparison plan actual MH/SA spending per enrollee $129 $149 $173 $190 47.3%
5 Actual MH/SA spending per user $881 $867 $981 $971 10.2%
6 Comparison plan acutal MH/SA spending per user $736 $800 $871 $906 23.1%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 16.13%
(15.68%, 16.64%)
18.19%
(17.64%, 18.79%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 18.08%
(17.58%, 18.58%)
20.38%
(19.88%, 20.92%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.24%a
(-0.77%, 0.27%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$22.60a
($84.40, $39.30)
  1. Not significant at p<0.05.

 

Table IV.C.7. FFS-S Adult MH/SA Use and Spending -- Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 17.0% 18.2% 19.7% 21.0% 23.5%
2 Comparison plan actual probability of MH/SA use 17.5% 18.6% 19.8% 21.0% 20.0%
3 Actual MH/SA spending per enrollee $131 $147 $143 $156 19.1%
4 Comparison plan actual MH/SA spending per enrollee $129 $149 $173 $190 47.3%
5 Actual MH/SA spending per user $768 $814 $726 $742 -3.4%
6 Comparison plan acutal MH/SA spending per user $736 $800 $871 $906 23.1%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 17.65%
(17.16%, 18.17%)
20.30%
(19.78%, 20.87%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 18.08%
(17.58%, 18.58%)
20.38%
(19.87%, 20.91%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity 0.35%a
(-0.17%, 0.91%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$201.99
(-$255.90, -$148.10)
  1. Not significant at p<0.05 level

 

Table IV.C.8. HMO-W1 Adult MH/SA Use and Spending-Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 15.6% 16.5% 18.1% 19.2% 23.1%
2 Comparison plan actual probability of MH/SA use 15.1% 16.5% 17.7% 19.0% 25.8%
3 Actual MH/SA spending per enrollee $101 $113 $147 $168 66.3%
4 Comparison plan actual MH/SA spending per enrollee $107 $122 $138 $153 43.0%
5 Actual MH/SA spending per user $647 $688 $814 $875 35.2%
6 Comparison plan acutal MH/SA spending per user $711 $739 $784 $806 13.4%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 15.97%
(15.51%, 16.41%)
18.61%
(18.10%, 19.14%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 15.87%
(15.41%, 16.31%)
18.20%
(17.63%, 18.66%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity 0.32%a
(-0.22%, 0.85%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity $32.96a
(-$40.90, $106.81)
  1. Not significant at p<0.05.

 

Table IV.C.9. HMO-NE Adult MH/SA Use and Spending -- Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 15.6% 15.9% 16.0% 16.6% 6.4%
2 Comparison plan actual probability of MH/SA use 14.1% 16.0% 17.5% 18.9% 34.0%
3 Actual MH/SA spending per enrollee $131 $139 $151 $169 20.9%
4 Comparison plan actual MH/SA spending per enrollee $113 $141 $163 $184 62.8%
5 Actual MH/SA spending per user $839 $876 $947 $1,019 21.5%
6 Comparison plan acutal MH/SA spending per user $749 $884 $932 $972 29.8%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- and post-parity 15.80%
(15.44%, 16.16%)
16.18%
(15.87%, 16.52%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 14.96%
(14.63%, 15.31%)
18.07%
(17.70%, 18.43%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -2.73%
(-3.30%, -2.20%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$77.82
(-$140.11, -$15.53)

Adult SA Service Use and Spending: Before-after-parity Analysis

Overview and Model

The before-after-parity analysis of adult substance abuse (SA) service utilization and spending was conducted using two-part models that estimated the probability of SA service use and spending for those who used these services.

The estimates for the probability of SA service use were based on a logit regression model that contained age, gender, and relationship to the FEHB plan contract holder. The conditional SA service spending regression model included age, gender, relationship of the FEHB plan contract holder, diagnosis, and a dummy variable indicating whether the year under study was before or after implementation of the parity policy.

Applying the Model

Table IV.D.0 summarizes the results of the before-after-parity analysis of the impact of parity on SA service use and conditional spending on SA services for adults in the nine selected FEHB plans. Column 2 reports the absolute expected change from pre- to post-parity in the probability of using any SA services and the significance of this estimate at the 5% probability level.

Table IV.D.0. Summary Across Plans for Adult SA Service Use and Spending -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4 Column 5
Absolute expected change from pre- to post-parity in probability of SA service use Percent change from pre- to post-parity in probability of SA service use Change from pre- to post-parity in SA service spending conditional on any SA service use Percent change from pre- to post-parity in SA service spending conditional on any SA service use
Plan Percentage Points Significance   Spending Significancea  
FFS-NAT 0.11% p<0.05 26.93% -$674.07 p<0.05 -33.99%
FFS-MA1 0.13% p<0.05 23.07% $202.57 NS 25.39%
FFS-MA2 0.19% p<0.05 37.40% $2.94 NS 0.43%
FFS-NE1 0.13% p<0.05 29.72% $76.64 NS 5.53%
FFS-NE2 0.15% p<0.05 38.54% $567.36 NS 37.92%
FFS-W 0.13% p<0.05 28.58% $167.16 NS 16.25%
FFS-S 0.18% p<0.05 34.71% -$48.44 NS -4.74%
HMO-W1 0.31% p<0.05 61.06% $1,130.62 p<0.05 1,245.18%
HMO-NE 0.15% p<0.05 7.22% $101.27 NS 20.37%
  1. NS indicates not significant at p<0.05.

Column 3 shows the percent change from pre- to post-parity in the probability of SA service use. Column 4 shows the pre- to post-parity change in spending on SA services for those adults who used SA services and the significance of this estimate at the 5% probability level; the percentage change that this estimate represents is shown in Column 5.

Table IV.D.0 was derived from the plan-specific analysis results shown in Tables IV.D.1 through IV.D.9. To illustrate the links between Tables IV.D.1 through IV.D.9 and the summarized results in Table IV.D.0, we again use the FFS-NAT plan as an illustrative example.

Row 1 of Table IV.D.0 summarizes the before-after-parity results on SA service use and spending analyses for adults in the FFS-NAT plan; the detailed FFS-NAT plan results for these analyses are reported in Table IV.D.1.

Panel 1 of Table IV.D.1 reports descriptive statistics for adults in the FFS-NAT plan on the actual probability that an enrollee will use any SA services (Row 1), actual SA services spending per enrollee (Row 2), and actual SA services spending per SA services user (Row 3).

Row 1 of Panel 1 of Table IV.D.1 shows the actual probability of SA service use per enrollee in the FFS-NAT plan in the pre-parity period as 0.43% in both 1999 and 2000 (Column 1), and in the post-parity period as 0.53% in 2001 and 0.49% in 2002 (Column 2). This represents a 25% increase in the probability of SA service use from pre- to post-parity for adults in the FFS-NAT plan.

Table IV.D.1. FFS-NAT Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.43% 0.43% 0.53% 0.49% 25.00%
2 Actual SA spending per enrollee $6.50 $6.71 $7.03 $7.97 14.3%
3 Actual SA spending per SA user $1,834.35 $1,773.29 $1,318.79 $1,634.12 -10.9%
P
A
N
E
L

2

4 Expected probability of SA use 0.43%
(0.37%, 0.48%)
0.42%
(0.36%, 0.47%)
0.55%
(0.49%, 0.61%)
0.53%
(0.47%, 0.59%)
 
5 Average expected probability of SA use pre- and post-parity 0.42%
(0.37%, 0.48%)
0.54%
(0.48%, 0.60%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.11%
(0.04%, 0.18%)
26.93%
P
A
N
E
L

3

7 Expected SA spending per SA user $1,998.20
($1,401.98, $2,820.35)
$1,968.35
($1,424.18, $2,748.72)
$1,177.45
($886.16, $1,472.07)
$1,440.96
($1,108.28, $1,831.81)
 
8 Average expected pre- and post-parity SA spending per user $1,983.27
($1,418.98, $2,783.00)
$1,309.20
($1,025.33, $1,626.76)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use -$674.07
(-$1,436.36, -$41.73)
-33.99%

Row 2 of Panel 1 of Table IV.D.1 shows the actual SA service spending per enrollee in the FFS-NAT plan in the pre-parity period as $6.50 in 1999 and $6.71 in 2000 (Column 1), and in the post-parity period as $7.03 in 2001 and $7.97 in 2002 (Column 2). The change in SA service use spending per enrollee from pre- to post-parity increased by 14.3% (Column 3).

Finally, Row 3 of Panel 1 of Table IV.D.1 shows the actual SA service spending per user of SA services in the FFS-NAT plan in the pre-parity period as $1,834.35 in 1999 and $1,773.29 in 2000 (Column 1), and in the post-parity period as $1,318.79 in 2001 and $1,634.12 in 2002 (Column 2), resulting in a 10.9% decrease in SA service spending per SA service user from pre- to post-parity (Column 3).

Panel 2 of Table IV.D.1 reports estimates from the regression model on the probability that an enrollee of the FFS-NAT plan will use SA services, along with confidence intervals (shown in parentheses) for these estimates. Row 4 of Panel 2 reports the estimated probability of SA service use in the FFS-NAT plan in the pre-parity period as 0.43% in 1999 and 0.42% in 2000 (Column 1), and in the post-parity period as 0.55% in 2001 and 0.53% in 2002 (Column 2). Row 5 of Panel 2 shows the resulting annual average probability of SA service use as 0.42% in the pre-parity period (Column 1) and 0.54% in the post-parity period (Column 2). Row 6 of Panel 2 shows that for the FFS-NAT plan, the probability of using SA services increased by 0.11 percentage points, which amounts to a 26.93% increase in SA services use from pre- to post-parity, an increase significantly different from zero at the 95% confidence level (Row 6). These impact estimates are also reported on Row 1 of Columns 1, 2, and 3 in Table IV.D.0.

Panel 3 of Table IV.D.1 reports estimates from the regression model on expected annual SA spending for users of SA services and the 95% confidence intervals for these estimates. Row 7 of Panel 3 shows the expected spending on SA services for SA service users in the FFS-NAT plan in the pre-parity period as $1,998.20 in 1999 and $1,968.35 in 2000 (Column 1), and in the post-parity period as $1,177.45 in 2001 and $1,440.96 in 2002 (Column 2). Row 8 shows the resulting expected annual SA services spending in the pre-parity period as $1,983.27 (Column 1) and $1,309.20 in the post-parity period (Column 2). Row 9 of Panel 3 shows that for the FFS-NAT plan, SA services spending for those who used these services decreased $674.07 from pre- to post-parity, which amounts to a decrease of 33.99% (Column 3). As its confidence interval of -$1,436.36 to -$41.73 does not include zero, the -$674.07 estimate is significantly different from zero. The -$674.07 spending estimate and 33.99% decrease in spending from pre- to post-parity are also reported on Row 1 of Table IV.D.1 in Columns 4 and 5, respectively.

Table IV.D.2. FFS-MA1 Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.54% 0.59% 0.65% 0.72% 40.00%
2 Actual SA spending per enrollee $5.52 $4.95 $6.37 $7.79 33.3%
3 Actual SA spending per SA user $1,023.10 $840.97 $985.00 $1,077.41 5.3%
P
A
N
E
L

2

4 Expected probability of SA use 0.58%
(0.51%, 0.65%)
0.59%
(0.52%, 0.66%)
0.71%
(0.63%, 0.79%)
0.72%
(0.65%, 0.80%)
 
5 Average expected probability of SA use pre- and post-parity 0.58%
(0.52%, 0.65%)
0.72%
(0.64%, 0.79%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.13%
(0.06%, 0.20%)
23.07%
P
A
N
E
L

3

7 Expected SA spending per SA user $821.87
(567.83, $1,100.37)
$773.95
($528.46, $1,033.09)
$1,012.21
($783.82, $1,245.79)
$988.75
($756.85, $1,225.35)
 
8 Average expected pre- and post-parity SA spending per user $797.91
($567.73, $1,045.89)
$1,000.48
($784.04, $1,228.24)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use $202.57a
(-$81.08, $472.08)
25.39%
  1. Not significant at p<0. 05.

 

Table IV.D.3. FFS-MA2 Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.50% 0.52% 0.65% 0.75% 60.00%
2 Actual SA spending per enrollee $4.04 $2.98 $4.09 $5.56 50.0%
3 Actual SA spending per SA user $803.80 $575.21 $628.55 $741.22 -7.8%
P
A
N
E
L

2

4 Expected probability of SA use 0.51%
(0.46%, 0.55%)
0.51%
(0.47%, 0.56%)
0.70%
(0.65%, 0.74%)
0.71%
(0.66%, 0.76%)
 
5 Average expected probability of SA use pre- and post-parity 0.51%
(0.47%, 0.56%)
0.70%
(0.65%, 0.75%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.19%
(0.15%, 0.24%)
37.40%
P
A
N
E
L

3

7 Expected SA spending per SA user $705.38
($570.53, $858.26)
$651.26
($525.57, $793.23)
$708.15
($566.88, $886.05)
$654.38
($521.06, $825.73)
 
8 Average expected pre- and post-parity SA spending per user $678.32
($555.74, $819.66)
$681.27
($536.72, $853.59)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use $2.94a
(-$187.33, $209.23)
0.4%
  1. Not significant at p<0.05.

 

Table IV.D.4. FFS-NE1 Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.44% 0.44% 0.55% 0.59% 50.00%
2 Actual SA spending per enrollee $5.66 $6.88 $9.45 $7.35 16.7%
3 Actual SA spending per SA user $1,295.83 $1,558.47 $1,708.88 $1,248.51 -3.6%
P
A
N
E
L

2

4 Expected probability of SA use 0.44%
(0.39%, 0.50%)
0.44%
(0.39%, 0.49%)
0.57%
(0.51%, 0.64%)
0.57%
(0.51%, 0.64%)
 
5 Average expected probability of SA use pre- and post-parity 0.44%
(0.39%, 0.50%)
0.57%
(0.51%, 0.64%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.13%
(0.07%, 0.20%)
29.72%
P
A
N
E
L

3

7 Expected SA spending per SA user $1,421.01
($1,041.37, $1,790.95)
$1,348.95
($993.03, $1,750.21)
$1,551.54
($1,188.17, $1,932.31)
$1,371.69
($1,052.15, $1,743.86)
 
8 Average expected pre- and post-parity SA spending per user $1,384.98
($1,038.20, $1,755.93)
$1,461.62
($1,139.60, $1,804.51)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use $76.64a
(-$473.48, $573.84)
5.53%
  1. Not significant at p<0.05.

 

Table IV.D.5. FFS-NE2 Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.40% 0.38% 0.53% 0.55% 50.00%
2 Actual SA spending per enrollee $8.66 $5.57 $10.99 $12.13 33.3%
3 Actual SA spending per SA user $2,186.06 $1,457.34 $2,086.36 $2,206.19 0.9%
P
A
N
E
L

2

4 Expected probability of SA use 0.39%
(0.33%, 0.47%)
0.39%
(0.32%, 0.46%)
0.54%
(0.46%, 0.62%)
0.54%
(0.45%, 0.62%)
 
5 Average expected probability of SA use pre- and post-parity 0.39%
(0.32%, 0.47%)
0.54%
(0.46%, 0.62%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.15%
(0.07%, 0.23%)
38.54%
P
A
N
E
L

3

7 Expected SA spending per SA user $1,511.55
($778.61, $2,309.66)
$1,481.23
($786.00, $2,179.94)
$2,068.46
($1,461.19, $2,931.88)
$2,059.02
($1,427.85, $2,885.16)
 
8 Average expected pre- and post-parity SA spending per user $1,496.39
($803.69, $2,185.87)
$2,063.74
($1,436.52, $2,890.72)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use $567.36a
(-$435.02, $1,815.18)
37.92%
  1. Not significant at p<0.05.

 

Table IV.D.6. FFS-W Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.45% 0.47% 0.56% 0.62% 20.00%
2 Actual SA spending per enrollee $5.99 $3.39 $5.47 $8.78 50.0%
3 Actual SA spending per SA user $1,323.56 $720.69 $968.22 $1,410.99 6.6%
P
A
N
E
L

2

4 Expected probability of SA use 0.46%
(0.41%, 0.50%)
0.47%
(0.42%, 0.52%)
0.59%
(0.54%, 0.64%)
0.60%
(0.55%, 0.66%)
 
5 Average expected probability of SA use pre- and post-parity 0.46%
(0.42%, 0.51%)
0.59%
(0.55%, 0.65%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.13%
(0.08%, 0.18%)
28.58%
P
A
N
E
L

3

7 Expected SA spending per SA user $1,106.14
($826.15, $1,405.57)
$950.96
($687.78, $1,191.85)
$1,157.56
($915.74, $1,429.35)
$1,233.87
($958.73, $1,512.73)
 
8 Average expected pre- and post-parity SA spending per user $1,028.55
($774.72, $1,289.28)
$1,195.71
($932.32, $1,455.01)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use $167.16a
(-$192.84, $500.09)
16.25%
  1. Not significant at p<0.05.

 

Table IV.D.7. FFS-S Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.49% 0.54% 0.66% 0.73% 40.00%
2 Actual SA spending per enrollee $4.32 $6.60 $6.45 $7.54 100.0%
3 Actual SA spending per SA user $878.79 $1,216.35 $978.70 $1,027.82 17.0%
P
A
N
E
L

2

4 Expected probability of SA use 0.51%
(0.47%, 0.55%)
0.52%
(0.48%, 0.57%)
0.69%
(0.64%, 0.75%)
0.70%
(0.65%, 0.77%)
 
5 Average expected probability of SA use pre- and post-parity 0.52%
(0.47%, 0.56%)
0.70%
(0.65%,
6 Absolute expected change from pre- to post-parity in probability of SA use 0.18%
(0.12%, 0.23%)
34.71%
P
A
N
E
L

3

7 Expected SA spending per SA user $1,046.58
($808.85, $1,336.71)
$996.15
($753.84, $1,278.73)
$1,012.71
($800.96, $1,233.60)
$933.15
($725.91, $1,172.65)
 
8 Average expected pre- and post-parity SA spending per user $1,021.37
(787.35, $1,280.39)
$972.93
($774.02, $1,190.32)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use -$48.44a
(-$373.00, $255.28)
-4.74%
  1. Not significant at p<0.05.

 

Table IV.D.8. HMO-W1 Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.49% 0.53% 0.74% 0.89% 80.00%
2 Actual SA spending per enrollee $2.29 $1.72 $10.68 $8.75 $350.0%
3 Actual SA spending per SA user $471.17 $328.78 $1,437.50 $990.02 110.2%
P
A
N
E
L

2

4 Expected probability of SA use 0.50%
(0.42%, 0.59%)
0.51%
(0.43%, 0.60%)
0.81%
(0.70%, 0.91%)
0.83%
(0.72%, 0.93%)
 
5 Average expected probability of SA use pre- and post-parity 0.51%
(0.42%, 0.59%)
0.82%
(0.71%, 0.92%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.31%
(0.20%, 0.42%)
61.06%
P
A
N
E
L

3

7 Expected SA spending per SA user $22.60
(-$686.37, $390.01)
$159.00
(-$537.43, $529.57)
$1,224.91
($823.02, $1,729.10)
$1,217.94
($825.96, $1,727.58)
 
8 Average expected pre- and post-parity SA spending per user $22.60
(-$686.37, $390.01)
$159.00
(-$537.43, $529.57)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use $1,130.62
($558.51, $2,144.97)
1,245.18%

 

Table IV.D.9. HMO-NE Adult SA Service Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

1 Actual probability of SA use 1.98% 2.22% 2.18% 2.32% 15.00%
2 Actual SA spending per enrollee $12.58 $10.61 $15.03 $16.42 23.1%
3 Actual SA spending per SA user $636.81 $478.73 $690.87 $708.49 11.1%
P
A
N
E
L

2

4 Expected probability of SA use 2.09%
(2.00%, 2.19%)
2.11%
(2.01%, 2.21%)
2.24%
(2.13%, 2.35%)
2.26%
(2.16%, 2.37%)
 
5 Average expected probability of SA use pre- and post-parity 2.10%
(2.00%, 2.20%)
2.25%
(2.14%, 2.36%)
6 Absolute expected change from pre- to post-parity in probability of SA use 0.15%
(0.02%, 0.28%)
7.22%
P
A
N
E
L

3

7 Expected SA spending per SA user $522.85
($328.19, $656.77)
$476.24
($316.15, $605.42)
$600.04
($474.50, $763.08)
$600.09
($466.15, $789.06)
 
8 Average expected pre- and post-parity SA spending per user $497.23
($343.68, $616.11)
$601.31
($472.18, $745.48)
9 Expected change from pre- to post-parity in SA service spending conditional on any SA service use $101.27a
(-$119.88, $366.95)
20.37%
  1. Not significant at p<0.05.

Findings Across Plans

Table IV.D.0 summarizes the results of the before-after-parity analysis of the impact of the parity policy on SA services use and spending for adults in the nine selected plans. Column 2 of Table IV.D.0 reports the estimate of the change in the probability of using any SA services. For all nine FEHB plans, estimates for the change from pre- to post-parity in the probability of SA service use were positive and significantly different from zero at the 5% probability level (as none of the confidence intervals for these estimates contained zero). While the magnitudes of these estimates ranged from a 7.34% increase in SA service use in HMO-NE to a 61.06% increase in HMO-W1, for seven of the nine plans, the estimates were in the 23% to 38% increase range for SA service use (Column 3 of Table IV.D.0).

The estimates of the impact of parity on conditional SA services spending showed more variation across the nine plans than did SA service use, as shown in Column 4 of Table IV.D.0. While the impact estimates on spending for two plans (FFS-NAT and FFS-S) were negative, the estimate was significantly different from zero only for the FFS-NAT plan, in which a $674.07 decrease in SA services spending represented a 33.99% spending decrease from pre- to post-parity.

Among the other seven plans, the positive impact estimates on SA services spending for users of SA services were significantly different from zero for only one of these plans -- HMO-W1. That plan experienced a substantial increase in SA services spending of $1,130.62 or 1,245%.

Discussion

The remarkably large SA services spending increase for HMO-W1 may be explained in part by the small number of SA service users in the HMO-W1 plan. Thus, with the exception of the HMO-W1 plan, the results of this before-after-parity analysis do not indicate significant growth in spending on SA services for SA service users, despite significant increases from pre- to post-parity in access to these services.

Adult SA Service Use and Spending: Difference-in-differences Analysis

Overview and Model

For the adult SA service use and spending difference-in-differences analysis, we compared the before-after-parity analysis data on SA service use and conditional spending reported in the previous section with data from a matched comparison group plan.

For each of the nine selected FEHB plans, we constructed a comparison group using administrative data from the Medstat MarketScan® database, employing the same matching procedures as described previously for the adult MH/SA use and spending difference-in-differences analysis. We likewise used the identical covariates and modeling procedures as described in the difference-in-differences analysis for adult MH/SA use and spending.

Applying the Model and Findings Across Plans

Table IV.E.0 summarizes the results across the nine FEHB plans from the difference-in-differences estimates for utilization and spending on SA services. This summary table was constructed from Tables IV.E.1 through IV.E.9, which show the detailed plan-specific findings.

Table IV.E.0. Summary Across Plans for Adult SA Service Use and Spending -- Difference-in-differences Analysis

Column 1 Column 2 Column 3
Difference-in-differences in probability of SA service use from pre- to post-parity Difference-in-differences estimate of conditional SA service spending from pre- to post-parity
Plan Estimate Significancea Estimate Significancea
FFS-NAT 0.01% NS -$288.41 p<0.05
FFS-MA1 0.08% NS $48.59 NS
FFS-MA2 0.15% p<0.05 -$23.02 NS
FFS-NE1 0.09% p<0.05 $179.92 NS
FFS-NE2 0.11% NS $600.47 NS
FFS-W 0.05% NS -$448.02 NS
FFS-S 0.16% p<0.05 -$664.80 NS
HMO-W1 0.25% p<0.05 $494.90 NS
HMO-NE 0.07% NS $171.17 NS
  1. NS indicates not significant at p<0.05.

Column 2 of Table IV.E.0 reports the parity policy impact estimates on rates of utilization of SA services. Positive impact estimates that were significantly different from zero at the 5% probability level were obtained for four of the nine FEHB plans, FFS-MA1, FFS-NE1, FFS-S, and HMO-W1.

Of all the plans, HMO-W1 had the largest increase from pre- to post-parity in the probability of SA service use, an estimate of 0.25 percentage points, which represents nearly a 50% increase in SA service utilization. FFS-S had the next largest estimate, 0.16 percentage points, which represents about a 32% increase from pre- to post-parity in the SA service utilization rate. For the remaining five plans, estimates were either not significantly different from zero or were considerably smaller in magnitude.

Column 3 reports the difference-in-differences estimates of SA service spending per user from pre- to post-parity. Eight plans had an impact on conditional spending on SA services that was not significantly different from zero; only FFS-NAT, which showed a pre- to post-parity decline of $288.41 in SA service spending, exhibited a significant SA service spending change. FFS-NAT also had one of the highest pre-parity SA spending rates of the nine plans, as shown in Column 2 of Table IV.E.1.

Table IV.E.1. FFS-NAT Adult SA Service Use and Spending -- Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.4% 0.4% 0.5% 0.5% 25.0%
2 Comparison plan actual probability of SA use 0.4% 0.5% 0.5% 0.5% 25.0%
3 Actual SA spending per enrollee $1,834.35 $1,773.29 $1,318.79 $1,634.12 -10.9%
4 Comparison plan actual SA spending per enrollee $1,348.01 $1,306.52 $1,477.01 $1,472.29 9.2%
5 Actual SA spending per SA user $6.50 $6.71 $7.30 $7.97 14.3%
6 Comparison plan acutal SA spending per SA user $5.77 $5.91 $7.13 $7.59 33.3%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.44%
(0.39%, 0.49%)
0.55%
(0.50%, 0.61%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.41%
(0.36%, 0.46%)
0.51%
(0.45%, 0.57%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.01%a
(-0.09%, 0.10%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user -$288.41
(-$504.51, -$72.30)
  1. Not significant at p<0.05.

Discussion

The impact of the parity policy on SA service use, taking into account secular trends, shows a mixed picture. While four of the FEHB plans experienced increases in SA service use, some substantial, the five other FEHB plans had no significant increases.

Results for the spending analysis, however, were less equivocal. The parity policy had little impact on conditional SA service spending; only one FEHB plan out of nine experienced any significant spending change. While SA spending in one plan, FFS-NAT, declined significantly after introduction of the parity policy, its initial pre-parity SA spending had been much higher than the spending in the other selected FEHB plans.

Table IV.E.2. FFS-MA1 Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.5% 0.6% 0.7% 0.7% 40.0%
2 Comparison plan actual probability of SA use 0.3% 0.3% 0.3% 0.4% 33.3%
3 Actual SA spending per enrollee $1,023.10 $840.97 $985.00 $1,077.41 5.3%
4 Comparison plan actual SA spending per enrollee $1,218.03 $1,884.41 $1,631.28 $1,967.83 61.6%
5 Actual SA spending per SA user $5.52 $4.95 $6.37 $7.79 33.3%
6 Comparison plan acutal SA spending per SA user $3.76 $6.28 $5.44 $7.62 100.0%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.58%
(0.52%, 0.65%)
0.70%
(0.63%, 0.77%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.33%
(0.26%, 0.39%)
0.36%
(0.30%, 0.43%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.08a
(-0.02%, 0.19%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user $48.59a
(-$805.98%, $903.16)
  1. Not significant at p<0.05.

 

Table IV.E.3. FFS-MA2 Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.5% 0.5% 0.7% 0.8% 60.0%
2 Comparison plan actual probability of SA use 0.3% 0.3% 0.3% 0.4% 33.3%
3 Actual SA spending per enrollee $803.80 $575.21 $628.55 $741.22 -7.8%
4 Comparison plan actual SA spending per enrollee $1,218.03 $1,884.41 $1,631.28 $1,967.83 61.6%
5 Actual SA spending per SA user $4.04 $2.98 $4.09 $5.56 50.0%
6 Comparison plan acutal SA spending per SA user $3.76 $6.28 $5.44 $7.62 100.0%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.52%
(0.46%, 0.58%)
0.71%
(0.63%, 0.77%0
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.33%
(0.26%, 0.39%)
0.36%
(0.30%, 0.43%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.15%
(0.03%, 0.25%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user -$23.02a
(-$878.44, $832.39)
  1. Not significant at p<0.05.

 

Table IV.E.4. FFS-NE1 Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.4% 0.4% 0.6% 0.6% 50.0%
2 Comparison plan actual probability of SA use 0.3% 0.3% 0.3% 0.4% 33.3%
3 Actual SA spending per enrollee $1,295.83 $1,558.47 $1,708.88 $1,248.51 -3.6%
4 Comparison plan actual SA spending per enrollee $1,218.03 $1,884.41 $1,631.28 $1,967.83 61.6%
5 Actual SA spending per SA user $5.66 $6.88 $9.45 $7.35 16.7%
6 Comparison plan acutal SA spending per SA user $3.76 $6.28 $5.44 $7.62 100.0%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.44%
(0.39%, 0.49%)
0.57%
(0.51%, 0.63%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.32%
(0.26%, 0.38%)
0.36%
(0.30%, 0.42%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.09%a
(0.0048%, 0.21%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user $179.92a
(-$795.00, $1,154.83)
  1. Not significant at p<0.05.

 

Table IV.E.5. FFS-NE2 Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use $8.66 $5.57 $10.99 $12.13 33.3%
2 Comparison plan actual probability of SA use $3.76 $6.28 $5.44 $7.62 100.0%
3 Actual SA spending per enrollee $2,186.06 $1,457.34 $2,086.36 $2,206.19 0.9%
4 Comparison plan actual SA spending per enrollee $1,218.03 $1,884.41 $1,631.28 $1,967.83 61.6%
5 Actual SA spending per SA user 0.4% 0.4% 0.5% 0.6% 50.0%
6 Comparison plan acutal SA spending per SA user 0.3% 0.3% 0.3% 0.4% 33.3%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.39%
(0.32%, 0.46%)
0.54%
(0.45%, 0.63%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.32%
(0.26%, 0.39%)
0.36%
(0.30%, 0.44%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.11%a
(-0.02%, 0.23%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user $600.47a
(-$588.86, $1,789.80)
  1. Not significant at p<0.05.

 

Table IV.E.6. FFS-W Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.5% 0.5% 0.6% 0.6% 20.0%
2 Comparison plan actual probability of SA use 0.4% 0.4% 0.4% 0.4% 0.0%
3 Actual SA spending per enrollee $1,323.56 $720.69 $968.22 $1,410.99 6.6%
4 Comparison plan actual SA spending per enrollee $1,807.78 $1,164.10 $2,212.18 $2,149.06 18.9%
5 Actual SA spending per SA user $5.99 $3.39 $5.47 $8.78 50.0%
6 Comparison plan acutal SA spending per SA user $6.34 $4.29 $9.37 $8.32 33.3%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.48%
(0.42%, 0.54%)
0.58%
(0.52%, 0.64%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.36%
(0.30%, 0.42%)
0.40%
(0.34%, 0.47%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.05%a
(-0.04%, 0.15%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user -$448.02a
(-$1,292.28, $396.24)
  1. Not significant at p<0.05.

 

Table IV.E.7. FFS-S Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.5% 0.5% 0.7% 0.7% 40.0%
2 Comparison plan actual probability of SA use 0.4% 0.4% 0.4% 0.4% 0.0%
3 Actual SA spending per enrollee $878.79 $1,216.35 $978.70 $1,027.82 17.0%
4 Comparison plan actual SA spending per enrollee $1,807.78 $1,164.10 $4,414.18 $2,149.06 18.9%
5 Actual SA spending per SA user $4.32 $6.60 $6.45 $7.54 100.0%
6 Comparison plan acutal SA spending per SA user $6.34 $4.29 $9.37 $8.32 33.3%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.50%
(0.45%, 0.56%)
0.70%
(0.63%, 0.77%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.36%
(0.30%, 0.42%)
0.40%
(0.34%, 0.47%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.16%
(0.06%, 0.25%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user -$664.80a
(-$1,498.26, $168.65)
  1. Not significant at p<0.05.

 

Table IV.E.8. HMO-W1 Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 0.5% 0.5% 0.7% 0.9% 80.0%
2 Comparison plan actual probability of SA use 0.4% 0.4% 0.4% 0.3% -25.0%
3 Actual SA spending per enrollee $471.17 $328.78 $1,437.50 $990.02 110.2%
4 Comparison plan actual SA spending per enrollee $1,463.00 $1,905.05 $1,518.31 $2,037.27 39.2%
5 Actual SA spending per SA user $2.29 $1.72 $10.68 $8.75 350.0%
6 Comparison plan acutal SA spending per SA user $5.29 $6.35 $5.53 $8.59 80.0%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 0.51%
(0.42%, 0.59%)
0.81%
(0.72%, 0.91%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.34%
(0.30%, 0.38%)
0.39%
(0.34%, 0.45%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.25%
(0.14%, 0.39%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user $494.90a
(-$150.30, $1,140.11)
  1. Not significant at p<0.05.

 

Table IV.E.9. HMO-NE Adult SA Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of SA use 2.0% 2.2% 2.2% 2.3% 15.0%
2 Comparison plan actual probability of SA use 0.4% 0.3% 0.4% 0.5% 25.0%
3 Actual SA spending per enrollee $636.81 $478.73 $690.87 $708.49 11.1%
4 Comparison plan actual SA spending per enrollee $1,505.11 $1,803.30 $1,935.54 $2,156.12 43.3%
5 Actual SA spending per SA user $12.58 $10.61 $15.03 $16.42 23.1%
6 Comparison plan acutal SA spending per SA user $5.44 $6.14 $7.55 $9.60 100.0%
P
A
N
E
L

2

7 Average expected probability of SA use pre- and post-parity 2.10%
(20..%, 2.21%)
2.25%
(2.14%, 2.34%)
 
8 Comparison plan average expected probability of SA use pre- and post-parity 0.36%
(0.32%, 0.39%)
0.44%
(0.39%, 0.49%)
P
A
N
E
L

3

9 Difference-in-differences in probability of SA use 0.06%a
(-0.10%, 0.23%)
P
A
N
E
L

4

10 Difference-in-differences estimate of SA spending per user $171.17a
(-$415.27, $757.61)
  1. Not significant at p<0.05.

Adult MH Use and Spending: Difference-in-differences Analysis

Overview and Model

For this analysis, we compared changes from pre- to post-parity on MH service use and conditional spending with data from a matched comparison group plan over the same time period. For each of the nine selected FEHB plans, we constructed a comparison group using administrative data from the Medstat MarketScan® database, employing the same matching procedures as described previously for the adult MH/SA and SA service use and spending difference-in-differences analyses. Likewise, we used the identical covariates and modeling procedures as described in those analyses.

Applying the Model and Findings Across Plans

Table IV.F.0 summarizes the results across the nine plans for service use and conditional spending on MH services. Table IV.F.0 was constructed from Tables IV.F.1 through IV.F.9, which show the detailed plan-specific findings. Table IV.F.0 mirrors the summary in Table IV.E.0 for the difference-in-differences analysis on adult SA service use and spending, reported in the previous section.

Table IV.F.0. Summary Across Plans for Adult MH Service Use and Spending--Difference-in differences Analysis

Column 1 Column 2 Column 3
Difference-in-differences in probability of MH service use from pre- to post-paritya Difference-in-differences estimate of MH conditional spending per user from pre- to post-paritya
Plan Estimate Significance Estimate Significance
FFS-NAT 0.07% NS -$63.25 p<0.05
FFS-MA1 -0.62% p<0.05 -$43.03 NS
FFS-MA2 0.91% p<0.05 -$21.62 NS
FFS-NE1 0.29% NS -$5.42 NS
FFS-NE2 -0.35% NS -$132.41 p<0.05
FFS-W 0.13% NS -$12.56 NS
FFS-S 0.53% NS $187.15 p<0.05
HMO-W1 -0.13% NS $19.85 NS
HMO-NE -2.62% p<0.05 -$77.32 p<0.05
  1. NS indicates not significant at p<0.05.

Column 2 of Table IV.F.0 reports the impact estimates on the probability of using any MH care. For only one plan, FFS-MA2, did we estimate an MH service use impact that was positive and significantly different from zero at the 5% probability level. That point estimate of 0.91 percentage points was small, representing about a 5% increase in the MH service utilization rate (not shown). In two plans, FFS-MA1 and HMO-NE, we obtained impact estimates that were negative and significantly different from zero. The remaining six plans had point estimates that were not significantly different from zero.

Column 3 of Table IV.F.0 reports impact estimates for MH spending by users of MH services. In none of the plans did we estimate impacts that were positive and significantly different from zero at the 5% probability level. In four plans (FFS-NAT, FFS-NE2, FFS-S, and HMO-NE), we obtained spending impact estimates that were negative and significantly different from zero.

Discussion

The results of these analyses suggest that growth in service use and spending on MH services in the selected FEHB plans were generally comparable to or somewhat below the growth in MH spending experienced by other large employers’ health plans.

Table IV.F.1. FFS-NAT Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 13.4% 14.3% 16.0% 16.8% 25.4%
2 Comparison plan actual probability of MH use 20.0% 20.8% 22.2% 23.6% 18.0%
3 Actual MH spending per enrollee $603.90 $636.71 $635.82 $675.30 11.8%
4 Comparison plan actual MH spending per enrollee $884.40 $951.35 $1,026.19 $1,039.17 17.5%
5 Actual MH spending per MH user $81.06 $91.13 $100.59 $112.58 $39.5%
6 Comparison plan acutal MH spending per MH user $176.65 $198.13 $227.36 $245.21 38.4%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 13.97%
(13.59%, 14.40%)
16.46%
(15.99%, 16.92%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 20.52%
(20.02%, 21.02%)
22.93%
(22.38%, 23.44%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use 0.07%a
(-0.46%, 0.58%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$63.25a
(-$82.55, -$43.94)
  1. Not significant at p<0.05.

 

Table IV.F.2. FFS-MA1 Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 18.2% 19.0% 20.0% 20.4% 12.1%
2 Comparison plan actual probability of MH use 16.4% 17.8% 18.7% 19.9% 21.3%
3 Actual MH spending per enrollee $1,146.40 $1,213.48 $1,277.30 $1,180.79 3.1%
4 Comparison plan actual MH spending per enrollee $882.77 $964.00 $1,025.55 $1,063.24 20.4%
5 Actual MH spending per MH user $208.66 $230.44 $255.54 $241.36 15.3%
6 Comparison plan acutal MH spending per MH user $144.81 $171.08 $191.31 $211.69 46.2%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 18.63%
(18.13%, 19.16%)
20.16%
(19.70%, 20.66%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 17.08%
(16.64%, 17.53%)
19.23%
(18.77%, 19.73%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use -0.62%
(-1.22%, -0.08%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$43.03a
(-$127.16, $41.11)
  1. Not significant at p<0.05.

 

Table IV.F.3. FFS-MA2 Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 17.9% 18.9% 20.8% 22.0% 22.9%
2 Comparison plan actual probability of MH use 16.4% 17.8% 18.7% 19.9% 21.3%
3 Actual MH spending per enrollee $712.97 $761.94 $827.54 $819.67 15.0%
4 Comparison plan actual MH spending per enrollee $882.77 $964.00 $1,025.55 $1,063.24 20.4%
5 Actual MH spending per MH user $127.89 $143.85 $172.07 $180.37 40.6%
6 Comparison plan acutal MH spending per MH user $144.81 $171.08 $191.31 $211.69 46.2%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 18.38%
(17.89%, 18.85%)
21.47%
(20.95%, 21.96%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 17.10%
(16.65%, 17.54%)
19.29%
(18.79%, 19.80%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use 0.91%
(0.34%, 1.45%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$21.62a
(-$105.47, $62.24)
  1. Not significant at p<0.05.

 

Table IV.F.4. FFS-NE1 Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 14.2% 15.7% 16.8% 18.0% 26.8%
2 Comparison plan actual probability of MH use 16.4% 17.8% 18.7% 19.9% 21.3%
3 Actual MH spending per enrollee $782.88 $791.20 $870.55 $868.29 10.9%
4 Comparison plan actual MH spending per enrollee $882.77 $964.00 $1,025.55 $1,063.24 20.4%
5 Actual MH spending per MH user $110.83 $124.17 $146.63 $155.98 40.5%
6 Comparison plan acutal MH spending per MH user $144.81 $171.08 $191.31 $211.69 46.2%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 15.15%
(14.69%, 15.61%)
17.63%
(17.12%, 18.10%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 17.11%
(16.65%, 17.59%)
19.29%
(18.81%, 19.80%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use 0.29%a
(-0.26%, 0.85%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$5.42a
(-$95.36, $84.52)
  1. Not significant at p<0.05.

 

Table IV.F.5. FFS-NE2 Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 13.8% 14.7% 15.9% 16.3% 18.1%
2 Comparison plan actual probability of MH use 16.4% 17.8% 18.7% 19.9% 21.3%
3 Actual MH spending per enrollee $1,239.08 $1,287.21 $1,211.38 $1,240.43 0.1%
4 Comparison plan actual MH spending per enrollee $882.77 $964.00 $1,025.55 $1,063.24 20.4%
5 Actual MH spending per MH user $171.43 $189.79 $193.12 $202.20 18.1%
6 Comparison plan acutal MH spending per MH user $144.81 $171.08 $191.31 $211.69 46.2%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 14.26%
(13.80%, 14.73%)
16.12%
(15.63%, 16.62%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 17.08%
(16.65%, 17.56%)
19.29%
(18.79%, 19.80%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use -0.35a
(-0.89%, 0.15%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$132.41
(-$246.48, -$18.35)
  1. Not significant at p<0.05.

 

Table IV.F.6. FFS-W Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 15.4% 16.7% 17.8% 18.7% 21.4%
2 Comparison plan actual probability of MH use 17.4% 18.5% 19.7% 20.9% 20.1%
3 Actual MH spending per enrollee $847.81 $851.76 $955.02 $927.76 9.4%
4 Comparison plan actual MH spending per enrollee $705.27 $782.37 $828.45 $869.52 23.4%
5 Actual MH spending per MH user $130.21 $141.99 $170.06 $173.76 33.8%
6 Comparison plan acutal MH spending per MH user $122.68 $144.41 $163.29 $181.62 48.0%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 16.21%
(15.77%, 16.66%)
18.83%
(18.38%, 19.30%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 18.05%
(17.57%, 18.52%)
20.54%
(20.03%, 21.07%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use 0.13%a
(-0.43%, 0.71%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$12.56a
(-$71.65, $46.54)
  1. Not significant at p<0.05.

 

Table IV.F.7. FFS-S Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 16.9% 18.1% 19.6% 20.9% 23.7%
2 Comparison plan actual probability of MH use 17.4% 18.5% 19.7% 20.9% 20.1%
3 Actual MH spending per enrollee $747.22 $781.40 $696.60 $709.76 -5.0%
4 Comparison plan actual MH spending per enrollee $705.27 $782.37 $828.45 $869.52 23.4%
5 Actual MH spending per MH user $126.28 $141.28 $136.46 $148.13 17.5%
6 Comparison plan acutal MH spending per MH user $122.68 $144.41 $163.29 $181.62 48.0%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 16.95%
(16.49%, 17.42%)
19.96%
(19.44%, 20.50%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 18.05%
(17.58%, 18.52%)
20.53%
(20.02%, 21.07%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use 0.53a
(-0.06%, 1.16%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$187.15
(-$238.02, -$136.28)
  1. Not significant at p<0.05.

 

Table IV.F.8. HMO-W1 Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 15.5% 16.3% 17.9% 19.0% 22.6%
2 Comparison plan actual probability of MH use 14.9% 16.3% 17.5% 18.9% 26.8%
3 Actual MH spending per enrollee $637.97 $686.30 $763.80 $842.87 32.1%
4 Comparison plan actual MH spending per enrollee $695.23 $718.08 $769.32 $773.31 11.2%
5 Actual MH spending per MH user $98.61 $111.67 $136.74 $159.33 60.6%
6 Comparison plan acutal MH spending per MH user $102.08 $115.45 $132.92 $144.75 42.2%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 15.87%
(15.38%, 16.35%)
18.39%
(17.89%, 18.92%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 15.47%
(15.03%, 15.93%)
18.12%
(17.62%, 18.63%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use -0.13a
(-0.67%, 0.48%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user $19.85a
(-$52.25, $91.94)
  1. Not significant at p<0.05.

 

Table IV.F.9. HMO-NE Adult MH Service Use and Spending--Difference-in-differences Analysis

  Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH use 14.3% 14.4% 14.5% 15.1% 5.6%
2 Comparison plan actual probability of MH use 13.9% 15.9% 17.3% 18.8% 35.3%
3 Actual MH spending per enrollee $829.17 $897.75 $937.56 $1,014.56 22.4%
4 Comparison plan actual MH spending per enrollee $769.69 $852.00 $897.78 $929.69 20.8%
5 Actual MH spending per MH user $118.72 $128.84 $136.41 $152.69 28.6%
6 Comparison plan acutal MH spending per MH user $107.23 $135.28 $155.57 $174.34 62.6%
P
A
N
E
L

2

7 Average expected probability of MH use pre- and post-parity 14.34%
(14.08%, 14.61%)
14.80%
(14.53%, 15.08%)
 
8 Comparison plan average expected probability of MH use pre- and post-parity 15.02%
(14.77%, 15.27%)
18.11%
(17.83%, 18.38%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH use -2.62%
(-3.02%, -2.23%)
P
A
N
E
L

4

10 Difference-in-differences estimate of MH spending per user -$77.32
(-$139.45, -$15.19)

Adult High Utilizers of MH/SA Care: Before-after-parity Analysis

Overview and Model

High levels of utilization and spending are directly tied to MH/SA inpatient utilization levels in the nine selected FEHB plans. Thus, in this section, we focus on the impact of the parity policy on the likelihood that MH/SA service users would have an inpatient episode.

In this analysis, we estimated logit regressions on whether adult users of MH/SA services were hospitalized in the pre- and post-parity periods. The explanatory variables in the regression model were age, gender, relationship to the contract holder, and diagnoses. The 95% confidence intervals for the estimates of inpatient MH/SA use were obtained via a bootstrap procedure.

Applying the Model

Table IV.G.0 summarizes the inpatient utilization results for the nine selected FEHB plans shown in Column 1. Column 2 reports the absolute expected change from pre- to post-parity in the probability of adult MH/SA inpatient use, and Column 3 shows the significance of this estimate at the 5% probability level. Finally, Column 4 reports the percentage change from pre- to post-parity in adult MH/SA inpatient use.

Table IV.G.0 was constructed from the plan-specific results in Tables IV.G.1 though IV.G.9. To illustrate the construction of Table IV.G.0, we once again turn to the FFS-NAT plan. Summary results for FFS-NAT are shown in Row 1 of Table IV.G.0 and detailed FFS-NAT results appear in Table IV.G.1.

Table IV.G.0. Summary Across Plans for Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Plan Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use Statistical Significancea Percentage change from pre- to post-parity in MH/SA inpatient use
FFS-NAT -0.10 NS -5.90%
FFS-MA1 -0.07 NS -5.20%
FFS-MA2 0.09 NS 7.84%
FFS-NE1 0.14 NS 11.73%
FFS-NE2 0.04 NS 2.90%
FFS-W 0.07 NS 6.27%
FFS-S 0.05 NS 3.71%
HMO-W1 0.57 p<0.05 44.22%
HMO-NE -0.06 NS -2.36%
  1. NS indicates not significant at p<0.05.

 

Table IV.G.1. FFS-NAT Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.85% 1.92% 1.65% 1.64% -15.79%
2. Expected probability of MH/SA inpatient use 1.74%
(1.50%, 2.00%)
1.67%
(1.44%, 1.92%)
1.62%
(1.42%, 1.85%)
1.59%
(1.41%, 1.83%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.71%
(1.47%, 1.93%)
1.61%
(1.43%, 1.82%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use -0.10%a
(-0.37%, 0.16%)
-5.90%
  1. Not significant at p<0.05.

Row 1 of Table IV.G.1 presents FFS-NAT’s actual MH/SA inpatient utilization rates in the pre-parity period as 1.85% in 1999 and 1.92% in 2000 (Column 2) and in the post-parity period as 1.65% in 2001 and 1.64% in 2002 (Column 3). Row 1, Column 4 shows the change from pre- to post-parity in MH/SA inpatient utilization as a 15.79% decline over the four years.

Row 2 of Table IV.G.1 reports the estimated MH/SA inpatient use for FFS-NAT in the pre-parity-period as 1.74% in 1999 and 1.67% in 2000 and in the post-parity period as 1.62% in 2001 and 1.59% in 2002. The 95% confidence interval for each estimate appears in parentheses below the estimate.

Row 3 shows the pre-parity average expected rates of MH/SA inpatient use as 1.71% (Column 2), and post-parity as 1.61% (Column 3). The 95% confidence intervals are shown in parentheses below.

Row 4 reports the FFS-NAT impact estimate for MH/SA inpatient utilization as a 0.10 percentage point decrease. The 95% confidence interval for this estimate is shown below and contains zero. Thus, the -0.10 MH/SA inpatient utilization estimate is not significantly different from 0 at the 5% probability level. Column 4 reports the percentage change from pre- to post-parity represented by the impact estimate as -5.90%. The impact estimate of -0.10% and percentage decrease of 5.90% also appear in Row 1 of Table IV.G.0.

Table IV.G.2. FFS-MA1 Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.29% 1.31% 1.38% 1.21% -7.69%
2. Expected probability of MH/SA inpatient use 1.30%
(1.10%, 1.51%)
1.36%
(1.16%, 1.58%)
1.24%
(1.06%, 1.44%)
1.28%
(1.09%, 1.46%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.33%
(1.14%, 1.54%)
1.26%
(1.08%, 1.44%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use -0.07%a
(-0.32%, 0.18%)
-5.2%
  1. Not significant at p<0.05.

 

Table IV.G.3. FFS-MA2 Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.16% 1.17% 1.17% 1.18% 0.00%
2. Expected probability of MH/SA inpatient use 1.10%
(0.91%, 1.28%)
1.13%
(0.95%, 1.29%)
1.21%
(1.03%, 1.42%)
1.19%
(1.02%, 1.38%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.11%
(0.94%, 1.28%)
1.20%
(1.04%, 1.38%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use 0.09%a
(-0.11%, 0.30%)
7.84%
  1. Not significant at p<0.05.

 

Table IV.G.4. FFS-NE1 Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.34% 1.10% 1.48% 1.23% -7.69%
2. Expected probability of MH/SA inpatient use 1.18%
(0.96%, 1.40%)
1.23%
(1.00%, 1.46%)
1.37%
(1.16%, 1.60%)
1.33%
(1.12%, 1.55%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.21%
(1.00%, 1.42%)
1.35%
(1.15%, 1.55%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use 0.14%a
(-0.11%, 0.40%)
11.73%
  1. Not significant at p<0.05.

 

Table IV.G.5. FFS-NE2 Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.74% 1.35% 1.80% 1.41% -17.65%
2. Expected probability of MH/SA inpatient use 1.56%
(1.19%, 1.94%)
1.50%
(1.16%, 1.83%)
1.64%
(1.30%, 1.99%)
1.51%
(1.21%, 1.88%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.53%
(1.19%, 1.87%)
1.58%
(1.27%, 1.92%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use 0.04%a
(-0.36%, 0.45%)
2.9%
  1. Not significant at p<0.05.

 

Table IV.G.6. FFS-W Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.28% 1.09% 1.33% 1.25% 0.00%
2. Expected probability of MH/SA inpatient use 1.21%
(1.03%, 1.42%)
1.14%
(0.98%, 1.34%)
1.23%
(1.07%, 1.40%)
1.27%
(1.10%, 1.46%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.18%
(1.02%, 1.37%)
1.25%
(1.10%, 1.41%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use 0.07%a
(-0.12%, 0.27%)
6.27%
  1. Not significant at p<0.05.

 

Table IV.G.7. FFS-S Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.02% 1.27% 1.34% 1.31% 30.00%
2. Expected probability of MH/SA inpatient use 1.30%
(1.08%, 1.57%)
1.16%
(0.95%, 1.39%)
1.33%
(1.13%, 1.63%)
1.22%
(1.01%, 1.48%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.23%
(1.02%, 1.45%)
1.27%
(1.09%, 1.53%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use 0.05%a
(-0.17%, 0.31%)
3.71%
  1. Not significant at p<0.05.

 

Table IV.G.8. HMO-W1 Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 1.47% 1.15% 1.97% 1.74% 13.33%
2. Expected probability of MH/SA inpatient use 1.18%
(0.86%, 1.52%)
1.39%
(1.04%, 1.73%)
1.81%
(1.46%, 2.20%)
1.90%
(1.56%, 2.25%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 1.29%
(0.98%, 1.61%)
1.86%
(1.52%, 2.21%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use 0.57%
(0.15%, 0.98%)
44.22%
  1. Not significant at p<0.05.

 

Table IV.G.9. HMO-NE Adult MH/SA Inpatient Use -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
1. Actual probability of MH/SA inpatient use 2.89% 2.70% 2.27% 2.93% 0.00%
2. Expected probability of MH/SA inpatient use 2.66%
(2.26%, 3.19%)
2.70%
(2.30%, 3.33%)
2.45%
(2.04%, 2.97%)
2.78%
(2.38%, 3.27%)
 
3. Average expected probability of MH/SA inpatient use pre- and post-parity 2.68%
(2.29%, 3.29%)
2.62%
(2.24%, 3.08%)
 
4.  Absolute expected change from pre- to post-parity in probability of MH/SA inpatient use -0.06%a
(-0.48%, 0.38%)
-2.36%
  1. Not significant at p<0.05.

Findings Across Plans

Table IV.G.0 summarizes the results for all nine selected FEHB plans. It reports MH/SA inpatient use impact estimates and the associated percentage change for each plan. For eight of the nine plans, no significant change (at the 5% probability level) occurred from pre- to post parity in the rate of inpatient utilization. HMO-W1 had the lone significant impact estimate; inpatient utilization increased about 44% from pre- to post-parity in this plan.

Discussion

The lack of significant findings on the impact of parity on inpatient utilization rates was not due to imprecise estimates (i.e., the confidence intervals for the estimates were fairly narrow) but rather to the small magnitude of the impact estimates. For seven of the eight plans in which no significant change in MH/SA inpatient utilization from pre- to post-parity was observed, the impact estimate represented less than an 8% change from pre- to post-parity.

In HMO-W1, which showed the only significant impact estimate, inpatient utilization increased substantially from pre- to post-parity. This change appears to be part of a general expansion in MH/SA utilization in HMO-W1, which behaves consistently different from the other eight plans.

Adult Out-of-pocket spending on MH/SA: Before-after-parity Analysis

Overview and Model

In this section, we analyzed the impact of parity on out-of-pocket costs for adult users of MH/SA services. The regression model we employed was estimated on adult beneficiaries who used MH/SA services. This model controlled for age, gender, relation to contract holder, and diagnosis.

Applying the Model

Table IV.H.0 summarizes the plan-specific results for the impact of parity on out-of-pocket costs (i.e. costs incurred by the beneficiary such as deductibles, co-payments, and costs not otherwise covered by insurance) for adult users of all MH/SA services, including inpatient, outpatient, laboratory, and pharmaceutical services. Table IV.H.0 was constructed from the detailed plan-specific results, shown in Tables IV.H.1 through IV.H.9. To illustrate how the estimates on Table IV.H.0 were constructed, we again use Table IV.H.1, which summarizes the per user out-of-pocket spending results for FFS-NAT, as an example.

Table IV.H.0. Summary Across Plans for Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4
Plan Expected change from pre- to post-parity in out-of-pocket MH/SA spending per user Percent expected change from pre- to post-parity in out-of-pocket MH/SA spending per user Percent change from pre-to post-parity in proportion of MH/SA spending due to out-of-pocket spending
Estimate Significance
1. FFS-NAT $14.80 p<0.05 7.14% 0.32%
2. FFS-MA1 -$25.15 p<0.05 -8.51% -15.84%
3. FFS-MA2 -$16.18 p<0.05 -9.55% -24.09%
4. FFS-NE1 -$15.56 p<0.05 -7.83% -21.95%
5. FFS-NE2 -$52.57 p<0.05 -15.90% -16.78%
6. FFS-W -$30.05 p<0.05 -14.84% -28.19%
7. FFS-S -$68.31 p<0.05 -32.86% -28.24%
8. HMO-W1 $51.26 p<0.05 141.41% 64.37%
9.  HMO-NE $48.30 p<0.05 67.50% 42.17%
  1. NS indicates not significant at p<0.05.

 

Table IV.H.1. FFS-NAT Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $31 $35 $38 $42 35.5%
2 Actual MH/SA out-of-pocket spending per user $231 $243 $239 $252 9.1%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $209.39
($197.63, $225.45)
$205.45
($193.52, $222.14)
$224.25
($213.32, $236.73)
$220.19
($209.29, $232.35)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $207.42
($195.73, $223.62)
$222.22
($211.59, $234.45)
5 Average expected probability of SA use pre- and post-parity $14.80
($5.17, $23.86)
7.14%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $590.06 $630.16  
7 Expected out-of-pocket spending share per user 0.3515 0.3526
8 Expected change from pre- to post-parity in out-of-pocket spending share per user 0.0011 0.32%

Panel 1 of Table IV.H.1 presents descriptive statistics for FFS-NAT on MH/SA out-of-pocket spending per enrollee (Row 1) and per user (Row 2). The change in the per-enrollee figures reflects the growing number of users as well as the change in insurance protection resulting from implementing the parity policy.

Panel 2 shows estimates of the impact of parity on out-of-pocket spending for MH/SA based on a regression model on out-of-pocket spending per user. Rows 3, 4, and 5 of Panel 2 report the estimated annual out-of-pocket spending per user, the average out-of-pocket spending per user during the pre- and post parity periods, and the estimated change in out-of-pocket MH/SA spending from pre- to post-parity, respectively. The 95% confidence interval for each estimate is presented in parentheses.

Row 3 shows that within the FFS-NAT plan, estimated out-of-pocket spending on MH/SA care per user increased from $209.39 in 1999 to $220.19 in 2002. Row 4 of Panel 2 shows that average out-of-pocket spending was estimated to be $207.42 pre-parity and $222.22 post-parity. Row 5 shows the before-after-parity change in out-of-pocket spending was $14.80 ($222.22 minus $207.42) with a 95% confidence interval of $5.17 to $23.86. The $14.80 estimated increase from pre- to post-parity in adult MH/SA out-of-pocket spending is significantly different from zero at a 5% probability level and represents a 7.14% out-of-pocket spending increase. The $14.80 and 7.14% figures also appear in Row 2 of summary Table IV.H.0.

Panel 3 combines these results on out-of-pocket spending per MH/SA user with earlier results on total MH/SA spending per user for FFS-NAT. Row 6 reports the average expected MH/SA spending per user for the pre-and post-parity periods, reported earlier in previous analyses. Thus, average spending per MH/SA user grew from $590.06 pre-parity to $630.16 post-parity. Row 7 shows the ratio of the average out-of-pocket MH/SA spending per user to the average total MH/SA spending per user as 0.35 (rounded to two decimal places) in both the pre- and post-parity periods. In other words, out-of-pocket MH/SA spending was 35% of total MH/SA spending in both periods.

Comparing the two ratios provides an indicator of the degree of financial protection afforded by the parity policy, taking into account growth in total MH/SA spending. The lower the ratios in Row 7, the lower the users’ expected out-of-pocket spending on MH/SA, and hence the greater the users’ financial protection.

Row 8 reports the change from pre- to post-parity in the ratios of out-of-pocket to total MH/SA spending as 0.0011, which represents a 0.32% percentage change, as reported in the last column of Row 8. This number is also reported as a summary statistic for FFS-NAT in the first row, last column of Table IV.H.1.

Table IV.H.2. FFS-MA1 Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $60 $66 $62 $62 3.3%
2 Actual MH/SA out-of-pocket spending per user $326 $343 $307 $299 -8.3%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $298.73
($286.48, $310.83)
$292.00
($279.47, $304.03)
$275.84
($265.98, $285.96)
$264.60
($255.18, $274.40)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $295.37
($282.98, $307.43)
$270.22
($260.50, $280.15)
5 Average expected probability of SA use pre- and post-parity -$25.15
(-$34.19, -$16.04)
-8.51%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $1,004.43 $1,091.86  
7 Expected out-of-pocket spending share per user 0.2941 0.2475
8 Expected change from pre- to post-parity in out-of-pocket spending share per user -0.0466 -15.84%

 

Table IV.H.3. FFS-MA2 Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $34 $38 $35 $39 14.7%
2 Actual MH/SA out-of-pocket spending per user $186 $198 $165 $177 -4.8%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $169.97
($160.80, $179.69)
$168.93
($159.11, $178.73)
$154.47
($148.91, $160.07
$152.06
($146.59, $157.51)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $169.45
($160.04, $178.78)
$153.27
($147.77, $158.49)
5 Average expected probability of SA use pre- and post-parity -$16.18
(-$23.60, -$9.23)
-9.55%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $629.51 $750.08  
7 Expected out-of-pocket spending share per user 0.2692 0.2043
8 Expected change from pre- to post-parity in out-of-pocket spending share per user -0.0648 -24.09%

 

Table IV.H.4. FFS-NE1 Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $32 $36 $34 $37 15.6%
2 Actual MH/SA out-of-pocket spending per user $222 $229 $203 $204 -8.1%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $199.60
($190.13, $209.44)
$197.80
($188.73, $206.76)
$184.72
($177.70, $193.20)
$181.57
($174.30, $189.90)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $198.70
($189.58, $207.72)
$183.15
($176.04, $190.73)
5 Average expected probability of SA use pre- and post-parity -$15.56
(-$24.34, -$6.53)
-7.83%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $693.28 $818.77  
7 Expected out-of-pocket spending share per user 0.2866 0.2237
8 Expected change from pre- to post-parity in out-of-pocket spending share per user -0.0629 -21.95%

 

Table IV.H.5. FFS-NE2 Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $51 $57 $51 $53 3.9%
2 Actual MH/SA out-of-pocket spending per user $368 $383 $315 $319 -13.3%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $336.45
($312.31, $360.51)
$324.88
($300.02, $349.71)
$283.67
($269.48, $298.38)
$272.53
($260.16, $286.39)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $330.67
($306.25, $355.52)
$278.10
($265.39, $292.21)
5 Average expected probability of SA use pre- and post-parity -$52.57
(-$71.16, -$34.72)
-15.90%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $1,133.87 $1,145.86  
7 Expected out-of-pocket spending share per user 0.2916 0.2427
8 Expected change from pre- to post-parity in out-of-pocket spending share per user -0.0489 -16.78%

 

Table IV.H.6. FFS-W Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $37 $39 $35 $38 2.7%
2 Actual MH/SA out-of-pocket spending per user $237 $231 $193 $204 -13.9%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $205.42
($194.87, $216.41)
$199.49
($189.41, $210.24)
$173.97
($166.28, $181.42)
$170.85
($163.37, $178.29)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $202.46
($192.25, $213.22)
$172.41
($165.11, $179.71)
5 Average expected probability of SA use pre- and post-parity -$30.05
(-$38.70, -$22.01)
-14.84%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $728.06 $863.43  
7 Expected out-of-pocket spending share per user 0.2781 0.1997
8 Expected change from pre- to post-parity in out-of-pocket spending share per user -0.0784 -28.19%

 

Table IV.H.7. FFS-S Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $36 $41 $28 $33 -8.3%
2 Actual MH/SA out-of-pocket spending per user $211 $227 $141 $159 -24.6%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $209.98
($196.21, $225.07)
$205.76
($193.07, $220.47)
$140.13
($133.11, $147.79)
$138.99
($132.24, $145.83)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $207.87
($195.01, $222.69)
$139.56
($133.30, $146.63)
5 Average expected probability of SA use pre- and post-parity -$68.31
(-$80.93, -$57.26)
-32.86%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $703.45 $658.12  
7 Expected out-of-pocket spending share per user 0.2995 0.2121
8 Expected change from pre- to post-parity in out-of-pocket spending share per user -0.0834 -28.24%

 

Table IV.H.8. HMO-W1 Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $9 $11 $18 $20 122.2%
2 Actual MH/SA out-of-pocket spending per user $58 $65 $100 $103 77.6%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $34.85
($31.86, $37.85)
$37.65
($34.81, $40.58)
$86.71
($82.83, $90.75)
$88.31
($84.24, $92.22)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $36.25
($33.36, $39.22)
$87.51
($83.45, $91.38)
5 Average expected probability of SA use pre- and post-parity $51.26
($46.97, $55.82)
141.41%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $509.59 $748.43  
7 Expected out-of-pocket spending share per user 0.0711 0.1169
8 Expected change from pre- to post-parity in out-of-pocket spending share per user 0.0458 64.37%

 

Table IV.H.9. HMO-NE Adult Out-of-pocket Spending on MH/SA -- Before-after-parity Analysis

  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-of-pocket spending per enrollee $13 $11 $15 $16 23.1%
2 Actual MH/SA out-of-pocket spending per user $94 $114 $123 $174 85.1%
P
A
N
E
L

2

3 Expected MH/SA out-of-pocket spending per user $71.29
($65.91, $77.07)
$71.83
($67.11, $77.00)
$119.36
($114.51, $124.01)
$120.36
($115.86, $124.92)
 
4 Average expected pre- and post-parity MH/SA out-of-pocket spending per user $71.56
($66.59, $77.00)
$119.86
($115.25, $124.48)
5 Average expected probability of SA use pre- and post-parity $48.30
($42.25, $54.48)
67.50%
P
A
N
E
L

3

6 Average expected pre- and post-parity MH/SA spending per user $661.99 $780.00  
7 Expected out-of-pocket spending share per user 0.1081 0.1537
8 Expected change from pre- to post-parity in out-of-pocket spending share per user 0.0456 42.17%

Findings Across Plans

Column 3 of Table IV.H.0 shows that in six of the nine selected plans, the parity policy was associated with a reduction in out-of-pocket spending per user, with out-of-pocket spending reductions ranging from 7.83% for adult service users in the FFS-NE1 plan to 32.86% for those in the FFS-S plan.

Nevertheless, across all nine plans, users of MH/SA care accrued substantial out-of-pocket spending reductions for those services. For example, for MH/SA users in the FFS-MA2 plan, average annual out-of-pocket spending after implementing parity was reduced by 9.55% (see Row 4 of Table IV.H.3). As shown in Column 2 of summary Table IV.H.0, the absolute dollar reductions in out-of-pocket spending for adult MH/SA care users ranged from $15.56 to $68.31. Thus, the overall impact of parity appears to involve modest reductions in out-of-pocket spending for some users of MH/SA care.

In contrast, users of MH/SA services in HMO-W1 experienced a large and significant increase (141%) in out-of-pocket spending, as did HMO-NE (68% increase), while FFS-NAT saw an out-of-pocket spending increase of 7% (Row 1, Column 3 of Table IV.H.0).

Focusing on the impact of the parity policy on financial protection, Column 4 of Table IV.H.0 presents the percent change from pre-to post-parity in the proportion of MH/SA spending that is due to out-of-pocket expenditures. As previously noted, adult MH/SA users in six of the nine plans experienced reductions in out-of-pocket burden. The magnitude of those declines in out-of-pocket spending, taking into account growth in spending attributable to secular trends, ranged from about 16% to 28%.

By contrast, HMO-W1 and HMO-NE both had notable increases in users’ out-of-pocket MH/SA burden, 64% and 42%, respectively, while FFS-NAT experienced a modest 0.32% increase in MH/SA users’ share of out-of-pocket spending.

Discussion

The large HMO-W1 out-of-pocket spending increase was driven by two phenomena. First, in the pre-parity period, HMO-W1 had lower cost sharing for some MH/SA services than it did for general medical care, a highly unusual situation in U.S. medical markets, including the FEHB Program (Hennessy and Barry, 2004). Second, the average number of visits per adult MH/SA user grew in the post-parity period. Taken together, these circumstances resulted in substantial increases in out-of-pocket spending for HMO-W1 MH/SA users.

In the case of FFS-NAT, a small but significant increase in out-of-pocket spending was estimated, amounting to a 7.14% increase. This was probably due to the relatively high cost-sharing requirements of FFS-NAT’s prescription drug plan, coupled with the national trend emphasizing pharmaceutical treatments among new users of care (DHHS, 1999).

For HMO-NE, no obvious explanation exists for the large increase in MH/SA out-of-pocket spending. HMO-NE imposed new cost-sharing increases in its prescription drug plan in the post-parity period. However, the magnitude of these cost-sharing increases was insufficient to explain HMO-NE’s large increase in out-of-pocket spending in the post-parity period

Taken together, these findings indicate that the parity policy increased MH/SA financial protection for most but not all of the beneficiaries in the selected FEHB plans.

Adult Out-of-pocket Spending on MH/SA: Difference-in-differences Analysis

Overview and Model

We compared the before-after-parity analysis data on MH/SA out-of-pocket spending reported in the previous section with data from a matched comparison group plan. For each of the nine selected FEHB plans, we constructed a comparison group using administrative data from the Medstat MarketScan® database, using the same matching procedures as described previously for the adult MH/SA use and spending difference-in-differences analysis.

In these regression models, out-of-pocket MH/SA spending for users of MH/SA services served as the dependent variable. The covariates in the models were the same as those used in the difference-in-differences analyses for adult MH/SA use and spending, e.g., age, gender, relationship to the health insurance plan contract holder, diagnosis, a dummy variable indicating whether the adult was enrolled in the FEHB plan under study or in the comparison plan, a dummy variable indicating whether the observed year was before or after the implementation of parity, and the interaction of the two dummy variables for FEHB plan and the post-parity time period.

The difference-in-differences out-of-pocket spending impact estimate was the coefficient estimate for the interaction term.

We constructed a 95% confidence interval based on the estimated standard errors, which were derived from the application of the generalized estimating equations (GEE) approach.

The simple hypothesis was that the parity policy would expand coverage and result in lower out-of-pocket spending for people that used MH/SA services, both to a greater degree than the secular trend.

Applying the Model

Table IV.I.0 summarizes the results of the estimation of the regression models on out-of-pocket spending for adult users of MH/SA services in all nine plans and is derived from the detailed plan-specific results in Tables IV.I.1 through IV.I.9. Each of Tables IV.I.1 through IV.I.9 provides descriptive results on yearly out-of-pocket MH/SA spending per enrollee and out-of-pocket MH/SA spending per user of MH/SA services for the FEHB plan and for its matched comparison plan.

Table IV.I.0. Summary Across Plans for Adult Out-of-pocket Spending on MH/SA -- Difference-in-differences Analysis

Plan MH/SA Out-of-pocket spending per user
Estimate Significancea
FFS-NAT $4.48 p<0.05
FFS-MA1 -$15.43 p<0.05
FFS-MA2 -$13.82 p<0.05
FFS-NE1 -$8.78 NS
FFS-NE2 -$48.12 p<0.05
FFS-W -$49.80 p<0.05
FFS-S -$87.06 p<0.05
HMO-W1 $25.16 p<0.05
HMO-NE $23.40 p<0.05
  1. NS indicates not significant at p<0.05.

Those tables also show the difference-in-differences estimates for MH/SA out-of-pocket spending and their 95% confidence intervals. By way of illustration, we again use FFS-NAT, Table IV.I.1 in this analysis, to illustrate how the summary of results in Table IV.I.0 was derived from the plan-specific tables.

In Panel 1 of Table IV.I.1, Row 1 shows the actual adult MH/SA out-of-pocket spending per enrollee in FFS-NAT for years 1999 and 2000 (pre-parity) and 2001 and 2002 (post-parity). (These results were previously reported in the before-after-parity out-of-pocket MH/SA spending analysis in Table IV.H.1.) Row 2 of Panel 1 shows these results for FFS-NAT’s comparison plan. Thus, in FFS-NAT, MH/SA out-of-pocket spending per enrollee increased from $31 in 1999 to $42 in 2002, a 35.5% spending increase (Row 1), while in the comparison plan, it increased from $23 to $33, a 43.5% increase over the same time period (Row 2).

Table IV.I.1. FFS-NAT Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $31 $35 $38 $42 35.5%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $23 $26 $30 $33 43.5%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $231 $243 $239 $252 9.1%
4 Comparison plan actual MH/SA out-of-pocket spending per user $116 $123 $135 $139 19.8%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   $4.48
($0.91, $8.06)

In Panel 2, Row 3, of Table IV.I.1, these results are shown per user of MH/SA services for both the FFS-NAT and its comparison plan. For example, Row 3 shows actual out-of-pocket spending per user was $231 in 1999 and $252 in 2002 for FFS-NAT, a 9.1% spending increase, while in the comparison plan, it increased from $116 to $139, a 19.8% increase over the same time period.

Panel 3 shows the difference-in-differences estimate of MH/SA out-of-pocket spending per user for the FFS-NAT plan as $4.48, which is significantly different from zero at a 5% probability level (i.e., its confidence interval did not include zero).

In other words, the FFS-NAT plan experienced a $4.48 increase from pre- to post-parity in MH/SA out-of-pocket spending after the influence of secular trends were taken into account. The $4.48 out-of-pocket spending increase for FFS-NAT is also reported in the first row of summary Table IV.I.0.

Findings Across Plans

For five of the nine FEHB plans, the difference-in-differences out-of-pocket MH/SA spending impact estimate was negative (a spending reduction from pre- to post-parity) and significantly different from zero at the 95% confidence level. For example, in the FFS-MA1 plan, the difference-in-differences estimate was -$15.43 and was significant at a 5% probability level. For one plan, FFS-NE1, the impact estimate was negative but not significantly different from zero (i.e., the confidence interval included zero). However, in three plans--FFS-NAT, HMO-NE, and HMO-W1--the out-of-pocket spending impact estimate was positive (a spending increase from pre- to post-parity) and significant.

Discussion

The MH/SA out-of-pocket spending results offer some evidence to support the hypothesis that the parity policy would expand coverage and result in lower out-of-pocket spending for beneficiaries that used MH/SA services.

As discussed earlier in the implementation analysis in chapter III and in the before-after-parity out-of-pocket spending analysis earlier in this chapter, the out-of-pocket spending increases for the FFS-NAT, HMO-NE, and HMO-W1 plans should be interpreted within the context of their plan benefit designs, which had some unusual features. For example, the prescription medication benefit in the FFS-NAT plan carried a high level of cost sharing, which would tend to increase out-of-pocket spending for FFS-NAT users of prescription medications.

Additionally, a secular trend emphasizing greater use of prescription medications in the post-parity period was evident.29 This secular trend would lead to even higher out-of-pocket spending. In the case of HMO-W1, in the pre-parity period, out-of-pocket copayment costs for initial MH/SA visits were actually lower than the out-of-pocket copayment costs for general medical out-patient visits. This is the one instance we studied in which parity for MH/SA care was associated with a higher level of copayments in the post-parity period for MH/SA services. Consequently, implementing parity in HMO-WI meant increased out-of-pocket costs for users of MH/SA care in this plan. We have no explanation, however, for HMO-NE’s significantly increased out-of-pocket spending in the post-parity period.

Table IV.I.2. FFS-MA1 Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $60 $66 $62 $62 3.3%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $28 $31 $31 $34 21.4%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $326 $343 $307 $299 -8.3%
4 Comparison plan actual MH/SA out-of-pocket spending per user $169 $171 $165 $167 -1.2%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   -$15.43
(-$26.14, -$4.73)

 

Table IV.I.3. FFS-MA2 Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $34 $38 $35 $39 14.7%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $28 $31 $31 $34 21.4%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $186 $198 $165 $177 -4.8%
4 Comparison plan actual MH/SA out-of-pocket spending per user $169 $171 $165 $167 -1.2%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   -$13.82
(-$23.96, -$3.67)

 

Table IV.I.4. FFS-NE1 Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $32 $36 $34 $37 15.6%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $28 $31 $31 $34 21.4%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $222 $229 $203 $204 -8.1%
4 Comparison plan actual MH/SA out-of-pocket spending per user $169 $171 $165 $167 -1.2%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   -$8.78
(-$21.14, $3.57)

 

Table IV.I.5. FFS-NE2 Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $51 $57 $51 $53 3.9%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $28 $31 $31 $34 21.4%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $368 $383 $315 $319 -13.3%
4 Comparison plan actual MH/SA out-of-pocket spending per user $169 $171 $165 $167 -1.2%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   -$48.12
(-$66.85, -$29.39)

 

Table IV.I.6. FFS-W Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $37 $39 $35 $38 2.7%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $22 $24 $28 $32 45.5%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $237 $231 $193 $204 -13.9%
4 Comparison plan actual MH/SA out-of-pocket spending per user $128 $131 $141 $154 22.2%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   -$49.80
(-$61.17, -$38.43)

 

Table IV.I.7. FFS-S Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $36 $41 $28 $33 -8.3%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $22 $24 $28 $32 45.5%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $211 $227 $141 $159 -24.6%
4 Comparison plan actual MH/SA out-of-pocket spending per user $126 $131 $141 $154 22.2%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   -$87.06
(-$99.73, -$74.38)

 

Table IV.I.8. HMO-W1 Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $9 $11 $18 $20 122.2%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $16 $18 $21 $22 37.5%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $58 $65 $100 $103 77.6%
4 Comparison plan actual MH/SA out-of-pocket spending per user $109 $107 $121 $118 8.3%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   $25.16
($17.98, $32.34)

 

Table IV.I.9. HMO-NE Adult Out-of-pocket Spending on MH/SA -- Difference-in-Differences Analysis

Column 1 Column 2 Column 3 Column 4
  Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual MH/SA out-to-pocket spending per enrollee $13 $11 $15 $16 23.1%
2 Comparison plan actual MH/SA out-of-pocket spending per enrollee $19 $22 $26 $29 52.6%
P
A
N
E
L

2

3 Actual MH/SA out-of-pocket spending per user $94 $114 $123 $174 85.1%
4 Comparison plan actual MH/SA out-of-pocket spending per user $132 $135 $150 $151 14.4%
P
A
N
E
L

3

5 Difference-in-differences estimate of MH/SA out-of-pocket spending per user   $23.40
($15.75, $31.04)

Child MH/SA Use and Spending: Before-after-parity Analysis

Overview and Model

In this section we address use and spending on MH/SA care for children. For this analysis, children were defined as under age 18 years. The before-after-parity analysis presented here for child MH/SA use and spending parallels that presented earlier for adults. That is, we employed the same two-part model and covariates and again used bootstrapping techniques to construct the 95% confidence intervals for our final estimates.

Applying the Model

Table IV.J.0 summarizes the MH/SA service use and conditional spending impact estimates for children in each of the nine selected FEHB plans. Column 2 of Table IV.J.0 reports the absolute percentage point change from pre-parity to post-parity in the probability of using any MH/SA services for continuously enrolled children. Column 3 of Table IV.J.0 reports the percentage change in children’s probability of MH/SA using the average pre-parity probability of use as a base. Column 4 of Table IV.J.0 reports the absolute change from pre- to post-parity in per user MH/SA spending for children using these services, while Column 5 indicates the percentage change from pre- to post-parity that the dollar values in Column 4 represent.

Table IV.J.0. Summary Across Plans for Child MH/SA Use and Spending -- Before-after-parity Analysis

Column 1 Column 2 Column 3 Column 4 Column 5
Plan Absolute percentage point change from pre- to post-parity in the probability of MH/SA use Percentage change from pre- to post-parity in probability of MH/SA use Change from pre- to post-parity in MH/SA spending conditional on any MH/SA use Percentage change from pre- to post-parity in MH/SA spending conditional on any MH/SA use
1. FFS-NAT 1.68% 24.71% $194.70 28.04%
2. FFS-MA1 2.75% 27.17% $273.26 27.42%
3. FFS-MA2 3.01% 30.01% $246.20 37.74%
4. FFS-NE1 2.28% 41.61% $390.20 57.28%
5. FFS-NE2 2.24% 33.94% $249.31 25.71%
6. FFS-W 1.57% 25.74% $335.52 46.34%
7. FFS-S 1.95% 27.31% $92.01 11.82%
8. HMO-W1 2.11% 40.58% $171.35 31.65%
9.  HMO-NE 0.81% 15.73% $354.94 77.04%

Tables IV.J.1 through IV.J.9 show the detailed plan-specific results from which the summary results in Table IV.J.0 were derived. To illustrate the construction of Table IV.J.0, we again turn to FFS-NAT, shown in Table IV.J.1, as an example.

Table IV.J.1. FFS-NAT Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 6.6% 7.0% 8.1% 8.9% 34.8%
2 Actual MH/SA spending per enrollee $44 $55 $71 $87 97.7%
3 Actual MH/SA spending per user $674 $773 $883 $988 46.6%
P
A
N
E
L

2

4 Expected probability of MH/SA use 6.55%
(6.40%, 6.71%)
7.05%
(6.89, 7.23%)
8.27%
(8.08%, 8.44%)
8.69%
(8.30%, 8.87%)
 
5 Average expected probability of MH/SA use pre- and post-parity 6.80%
(6.64%, 6.97%)
8.48%
(8.30%, 8.66%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 1.68%
(1.52%, 1.84%)
24.71%
P
A
N
E
L

3

7 Expected MH/SA spending per user $663.93
($626.99, $711.05)
$725.04
($682.44, $776.16)
$857.24
($810.55, $907.47)
$921.12
($863.68, $975.62)
 
8 Average expected pre- and post-parity MH/SA spending per user $694.48
($657.83, $739.86)
$889.18
($840.27, $941.14)
9 Expected change from pre- to post-parity in MH/SA spending per user $194.70
($142.71, $244.93)
28.04%

Panel 1 of Table IV.J.1 contains Rows 1, 2, and 3 and indicates the actual probability of child MH/SA use and spending pre- and post-parity. Row 1 shows the actual probability of child MH/SA use pre-parity as 6.6% in 1999 and 7.0% in 2000, and post-parity as 8.1% in 2001 and 8.9% in 2002. Column 3 of Row 1 indicates this represents a 34.8% increase from pre- (1999) to post-parity (2002) in the probability of child MH/SA use.

Row 2 of Table IV.J.1 shows the actual child MH/SA spending per enrollee pre-parity as $44 in 1999 and $55 in 2000 and post-parity as $71 in 2001 and $87 in 2002. Column 3 of Row 2 indicates this represents a 97.7% increase from pre- to post-parity in child MH/SA spending per enrollee.

Row 3 of Table IV.J.1 shows the actual child MH/SA spending per user pre-parity as $674 in 1999 and $773 in 2000 and post-parity as $883 in 2001 and $988 in 2002. Column 3 of Row 3 indicates this represents a 46.6% increase from pre- to post-parity (1999 to 2002) in spending per child MH/SA user.

Panel 2 of Table IV.J.1 contains Rows 4, 5, and 6 and reports the regression results for the probability of child MH/SA use in the FFS-NAT. Row 4 shows the pre-parity expected probability of child MH/SA use pre-parity as 6.55% in 1999 and 7.05% in 2000 and post-parity as 8.27% in 2001 and 8.69% in 2002. Row 5 indicates the average expected probability of child MH/SA use as 6.80% pre-parity and as 8.48% post-parity, with 95% confidence intervals in parentheses below the estimates.

Row 6 shows the expected change from pre- to post-parity in the probability of child MH/SA use as 1.68%, which is also shown in Row 1, Column 2 of summary Table IV.J.0. The 95% confidence intervals around the estimates are reported in parentheses. Column 3 of Row 6 represents this expected change in probability of child MH/SA use as a proportion of the pre-parity period average expected probability; this result, 24.71%, is also shown in Row 1, Column 3 of summary Table IV.J.0.

Panel 3 (Rows 7, 8, and 9) of Table IV.J.1 reports estimates from the regressions for the expected MH/SA spending per child user. Row 7 shows the expected MH/SA spending per user as $663.93 in 1999 and $725.04 in 2002 and post-parity as $857.24 in 2001 and $921.12 in 2002. Row 8 indicates the average expected spending per user pre-parity as $694.48 and post-parity as $889.18.

Row 9 shows the expected change from pre- to post-parity in MH/SA spending per user as an increase of $194.70, which is also shown in Row 1, Column 4 of summary Table IV.J.0. The 95% confidence interval around the estimate is reported in parentheses. Column 3 of Row 9 represents this spending estimate for child MH/SA care as a proportion of the pre-parity period average spending estimate. This result, 28.04%, is also shown in Row 1, Column 5 of summary Table IV.J.0.

Findings Across Plans

The estimated absolute change in the probability of children’s MH/SA use ranged from an increase of 0.81 percentage points for HMO-NE to 3.01 percentage points for FFS-MA2 (Column 2 of Table IV.J.0). None of the nine FEHB plans exhibited a decrease from pre- to post-parity in the probability of child MH/SA use. In terms of percentage change from pre- to post-parity as a proportion of the pre-parity probability of use, the estimates ranged from a 15.73% increase for HMO-NE to a 41.61% increase for FFS-NE2 (Column 3 of Table IV.J.0). HMO-W1 experienced nearly as high an increase as HMO-NE in the probability of MH/SA use for children, 40.58%.

For the remaining six plans, the pre- to post-parity increases in the probability of child MH/SA use ranged from about 25% to 34%. All of the estimated changes in the probability of child MH/SA use reported on Table IV.J.0 were significantly different from zero at the 5% probability level.

For all of the nine plans, the pre- to post-parity change in average per user MH/SA spending for children was significantly greater than zero at the 5% probability level and ranged from $92.01 for FFS-S to $390.20 for FFS-NE1 (Column 4 of Table IV.J.0). None of the plans experienced a decrease from pre- to post-parity in probability of spending on child MH/SA. The percentage changes represented by these absolute dollar changes ranged from 11.82% for FFS-S to 77.04% for HMO-NE, and in the 25% to 57% change range for the remaining seven plans (Column 5 of Table IV.J.0).

Discussion

The growth rates in the probability of children’s MH/SA use were generally higher than those observed for adults, although the base rates for children were much lower. For example, the majority of plans experienced probability of MH/SA use growth rates in the range of 3% to 17% for adults, compared to 25% to 34% for children. Likewise, growth in MH/SA spending for children was higher than that reported for adults.

The results for MH/SA use and spending for children in the nine selected FEHB plans mirror general trends in private health insurance overall (Zito, Safer, dosReis, et al., 2003; Glied and Cuellar, 2003). Later in this chapter, we consider such comparisons in greater detail in the analysis of the selected FEHB plans relative to privately insured populations in the same geographic regions. The relatively large post-parity increase in MH/SA use and spending for children makes this an important issue to examine carefully in the context of a control group.

Table IV.J.2. FFS-MA1 Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 9.7% 10.6% 12.3% 13.4% 38.1%
2 Actual MH/SA spending per enrollee $102 $128 $167 $183 79.4%
3 Actual MH/SA spending per user $1,057 $1,205 $1,360 $1,360 28.7%
P
A
N
E
L

2

4 Expected probability of MH/SA use 9.56%
(9.23%, 9.88%)
10.68%
(10.31%, 11.05%)
12.34%
(11.96%, 12.70%)
13.41%
(12.99%, 13.85%)
 
5 Average expected probability of MH/SA use pre- and post-parity 10.12%
(9.77%, 10.47%)
12.87%
(12.49%, 13.26%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 2.75%
(2.45%, 3.06%)
27.17%
P
A
N
E
L

3

7 Expected MH/SA spending per user $969.76
($853.38, $1,122.98)
$1,023.26
($906.53, $1,178.68)
$1,255.62
($1,158.17, $1,339.58)
$1,283.93
($1,204.58, $1,365.25)
 
8 Average expected pre- and post-parity MH/SA spending per user $996.51
($879.58, $1,150.40)
$1269.77
($1,198.41, $1,347.55)
9 Expected change from pre- to post-parity in MH/SA spending per user $273.26
($137.49, $389.60)
27.42%

 

Table IV.J.3. FFS-MA2 Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 9.5% 10.5% 12.3% 13.8% 45.3%
2 Actual MH/SA spending per enrollee $67 $83 $112 $138 106.0%
3 Actual MH/SA spending per user $699 $793 $914 $1,003 43.5%
P
A
N
E
L

2

4 Expected probability of MH/SA use 9.51%
(9.16%, 9.85%)
10.55%
(10.16%, 10.91%)
12.57%
(12.17%, 12.96%)
13.51%
(13.10%, 13.90%)
 
5 Average expected probability of MH/SA use pre- and post-parity 10.03%
(9.67%, 10.38%)
13.04%
(12.62%, 13.42%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 3.01%
(2.71%, 3.32%)
30.01%
P
A
N
E
L

3

7 Expected MH/SA spending per user $627.43
($570.86, $679.13)
$677.29
($616.33, $732.22)
$869.56
($811.44, $928.41)
$927.55
($866.88, $991.54)
 
8 Average expected pre- and post-parity MH/SA spending per user $652.36
($594.80, $703.51)
$898.55
($838.24, $955.01)
9 Expected change from pre- to post-parity in MH/SA spending per user $246.20
($179.05, $305.94)
37.74%

 

Table IV.J.4. FFS-NE1 Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 5.2% 5.7% 7.0% 8.5% 63.5%
2 Actual MH/SA spending per enrollee $40 $50 $72 $107 167.5%
3 Actual MH/SA spending per user $782 $872 $1,031 $1,263 61.5%
P
A
N
E
L

2

4 Expected probability of MH/SA use 5.20%
(4.91%, 5.50%)
5.76%
(5.43%, 6.09%)
7.46%
(7.10%, 7.85%)
8.07%
(7.69%, 8.52%)
 
5 Average expected probability of MH/SA use pre- and post-parity 5.48%
(5.16%, 5.81%)
7.76%
(7.40%, 8.17%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 2.28%
(1.95%, 2.70%)
41.61%
P
A
N
E
L

3

7 Expected MH/SA spending per user $636.40
($535.15, $735.73)
$725.97
($617.34, $831.23)
$1,004.48
($891.58, $1,136.68)
$1,138.29
($1,006.93, $1,281.37)
 
8 Average expected pre- and post-parity MH/SA spending per user $681.18
($573.47, $780.61)
$1,071.39
($951.37, $1,200.99)
9 Expected change from pre- to post-parity in MH/SA spending per user $390.20
($261.40, $541.75)
57.28%

 

Table IV.J.5. FFS-NE2 Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 5.8% 7.3% 8.3% 9.3% 60.3%
2 Actual MH/SA spending per enrollee $57 $88 $102 $131 129.8%
3 Actual MH/SA spending per user $983 $1,203 $1,232 $1,404 42.8%
P
A
N
E
L

2

4 Expected probability of MH/SA use 6.27%
(5.79%, 6.79%)
6.94%
(6.41%, 7.52%)
8.55%
(7.96%, 9.21%)
9.13%
(8.51%, 9.86%)
 
5 Average expected probability of MH/SA use pre- and post-parity 6.60%
(6.09%, 7.16%)
8.84%
(8.23%, 9.49%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 2.24%
(1.72%, 2.75%)
33.94%
P
A
N
E
L

3

7 Expected MH/SA spending per user $920.46
($749.41, $1,116.68)
$1,018.94
($834.35, $1,210.48)
$1,226.24
($1,049.87, $1,405.98)
$1,211.76
($1,033.60, $1,409.28)
 
8 Average expected pre- and post-parity MH/SA spending per user $969.70
($794.18, $1,163.04)
$1,219.00
($1,041.81, $1,391.25)
9 Expected change from pre- to post-parity in MH/SA spending per user $249.31
($34.67, $445.22)
25.71%

 

Table IV.J.6. FFS-W Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 5.7% 6.5% 7.1% 8.2% 43.9%
2 Actual MH/SA spending per enrollee $43 $58 $76 $97 125.6%
3 Actual MH/SA spending per user $754 $885 $1,071 $1,177 56.1%
P
A
N
E
L

2

4 Expected probability of MH/SA use 5.76%
(5.42%, 6.10%)
6.44%
(6.08%, 6.83%)
7.32%
(6.96%, 7.70%)
8.03%
(7.62%, 8.44%)
 
5 Average expected probability of MH/SA use pre- and post-parity 6.10%
(5.76%, 6.47%)
7.67%
(7.29%, 8.06%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 1.57%
(1.26%, 1.90%)
25.74%
P
A
N
E
L

3

7 Expected MH/SA spending per user $698.42
($591.03, $811.90)
$749.54
($633.43, $881.91)
$1,024.84
($895.81, $1,176.80)
$1,094.17
($959.57, $1,261.33)
 
8 Average expected pre- and post-parity MH/SA spending per user $723.98
($615.39, $850.67)
$1,059.51
($929.87, $1,214.76)
9 Expected change from pre- to post-parity in MH/SA spending per user $335.52
($207.87, $469.67)
46.34%

 

Table IV.J.7. FFS-S Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 6.8% 7.5% 8.5% 9.7% 42.6%
2 Actual MH/SA spending per enrollee $58 $71 $77 $97 67.2%
3 Actual MH/SA spending per user $859 $942 $898 $1,009 17.5%
P
A
N
E
L

2

4 Expected probability of MH/SA use 6.81%
(6.51%, 7.09%)
7.47%
(7.14%, 7.78%)
8.86%
(8.54%, 9.20%)
9.32%
(8.97%, 966.%)
 
5 Average expected probability of MH/SA use pre- and post-parity 7.14%
(6.83%, 7.44%)
9.09%
(8.76%, 9.41%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 1.95%
(1.68%, 2.22%)
27.31%
P
A
N
E
L

3

7 Expected MH/SA spending per user $753.57
($661.61, $842.33)
$803.19
($712.16, $896.97)
$824.06
($759.56, $905.41)
$916.71
($832.79, $1,03.99)
 
8 Average expected pre- and post-parity MH/SA spending per user $778.38
($691.48, $865.08)
$870.39
($801.87, $949.49)
9 Expected change from pre- to post-parity in MH/SA spending per user $92.01
($2.51, $195.38)
11.82%

 

Table IV.J.8. HMO-W1 Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 4.8% 5.7% 7.0% 7.6% 58.3%
2 Actual MH/SA spending per enrollee $28 $40 $50 $63 125.0%
3 Actual MH/SA spending per user $598 $711 $713 $834 39.5%
P
A
N
E
L

2

4 Expected probability of MH/SA use 4.90%
(4.46%, 5.41%)
5.48%
(4.97%, 5.99%)
7.02%
(6.49%, 7.56%)
7.61%
(7.02%, 8.17%)
 
5 Average expected probability of MH/SA use pre- and post-parity 5.20%
(4.72%, 5.71%)
7.32%
(6.76%, 7.85%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 2.11%
(1.65%, 2.59%)
40.58%
P
A
N
E
L

3

7 Expected MH/SA spending per user $499.59
($383.71, $623.02)
$583.36
$477.66, $719.25)
$670.42
($556.64, $796.57)
$755.21
($625.78, $893.18)
 
8 Average expected pre- and post-parity MH/SA spending per user $541.47
($439.69, $664.13)
$712.82
($596.01, $833.85)
9 Expected change from pre- to post-parity in MH/SA spending per user $171.35
($0.76, 332.55)
30.61%

 

Table IV.J.9. HMO-NE Child MH/SA Use and Spending -- Before-after-parity Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from Pre- to Post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 5.1% 5.2% 5.7% 6.2% 21.6%
2 Actual MH/SA spending per enrollee $28 $38 $55 $65 132.1%
3 Actual MH/SA spending per user $563 $722 $960 $1,054 87.2%
P
A
N
E
L

2

4 Expected probability of MH/SA use 4.96%
(4.68%, 5.26%)
5.35%
(5.03%, 5.66%)
5.78%
(5.44%, 6.08%)
6.15%
(5.79%, 6.48%)
 
5 Average expected probability of MH/SA use pre- and post-parity 5.15%
(4.86%, 5.46%)
5.96%
(5.61%, 6.27%)
6 Absolute percentage point change from pre- to post-parity in the probability of MH/SA use 0.81%
(0.46%, 1.16%)
15.73%
P
A
N
E
L

3

7 Expected MH/SA spending per user $419.11
($263.63, $560.01)
$502.31
($344.64, $636.59)
$805.55
($680.28, $944.35)
$825.75
($686.55, $1,003.82)
 
8 Average expected pre- and post-parity MH/SA spending per user $460.71
($318.24, $592.53)
$815.65
($690.78, $963.54)
9 Expected change from pre- to post-parity in MH/SA spending per user $354.94
($164.12, $576.12)
77.04%

Child MH/SA Use and Spending: Difference-in-differences Analysis

Overview and Model

We compared the before-after-parity-analysis data on children’s MH/SA use and conditional spending reported in the previous section with data from matched comparison group plans from the Medstat data set. For each of the nine selected FEHB plans, we constructed a comparison group by matching enrollees on the same basis as we employed previously for the difference-in-differences adult MH/SA use and spending analysis, as reported earlier in this chapter. Likewise, we constructed the difference-in-differences estimates for the probability of children’s MH/SA service use and conditional spending using the same model, covariates, and procedures that we used for the adult MH/SA use and spending difference-in-differences analysis.

Applying the Model

Table IV.K.0 summarizes the results of the difference-in-differences use and spending analyses for children in each of the nine selected FEHB plans, which are shown in Column 1. Column 2 reports the difference-in-differences estimates for the effect of parity on the probability of MH/SA use among children. Column 3 reports the difference-in-differences estimates for the effect of parity on MH/SA spending conditional on MH/SA use. The statistical significance of each estimate is also shown in its respective column.

Table IV.K.0. Summary Across Plans for Child MH/SA Use and Spending -- Difference-in-differences Analysis

Column 1 Column 2 Column 3
Difference-in-differences in probability of MH/SA use from pre- to post-paritya Difference-in-differences estimate of MH/SA spending per user from pre- to post-paritya
FEHB Plan Use estimate Significance of estimate Spending estimate Significance of estimate
FFS-NAT -0.39% NS -$174.04 p<0.05
FFS-MA1 0.48% NS -$48.47 NS
FFS-MA2 0.73% p<0.05 -$79.22 NS
FFS-NE1 -0.03% NS $20.36 NS
FFS-NE2 -0.04% NS -$128.84 NS
FFS-W -0.24% NS -$103.21 NS
FFS-S 0.06% NS -$320.00 p<0.05
HMO-W1 0.50% NS -$293.77 p<0.05
HMO-NE -1.51% p<0.05 -$307.22 p<0.05
  1. NS indicates not significant at p<0.05.

Summary Table IV.K.0 was derived from the plan-specific results shown in Tables IV.K.1 through IV.K.9, each of which shows the expected pre- and post-parity probability of child MH/SA service use30 and the difference-in-differences estimates of child MH/SA use and conditional spending when the FEHB plans are matched with their respective comparison group plans. To illustrate the links between the plan-specific Tables IV.K.1 through IV.K.9 and the summarized results in Table IV.K.0, we again use FFS-NAT as an example. Row 1 of Table IV.K.0 summarizes the use and spending difference-in-differences estimates for children in the FFS-NAT plan. The detailed FFS-NAT plan results are reported in Table IV.K.1.

Panel 1 of Table IV.K.1 contains six rows representing three pairs of descriptive results for the FFS-NAT plan and its comparison group plan. Rows 1 and 2 of Panel 1 show the actual probability of any child MH/SA use for FFS-NAT and its matched comparison plan, respectively. Likewise, Rows 3 and 4 show actual child MH/SA spending per enrollee and Rows 5 and 6 show actual child MH/SA spending per user of these services for FFS-NAT and its comparison plan.

Row 1 of Table IV.K.1 shows the probability of any MH/SA use for children in the FFS-NAT plan in the pre-parity period as 6.6% in 1999 and as 7.0% in 2000 (Column 1), and in the post-parity period as 8.1% in 2001 and 8.9% in 2002 (Column 2). The change in probability of child MH/SA use from pre- to post-parity (1999 to 2002) was 34.8% for the FFS-NAT plan (Column 3).

 

Table IV.K.1. FFS-NAT Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 6.6% 7.0% 8.1% 8.9% 34.8%
2 Comparison plan actual probability of MH/SA use 8.9% 10.0% 11.0% 12.3% 38.2%
3 Actual MH/SA spending per enrollee $44 $55 $71 $87 97.7%
4 Comparison plan actual MH/SA spending per enrollee $71 $88 $122 $150 111.3%
5 Actual MH/SA spending per user $674 $773 $883 $988 46.6%
6 Comparison plan actual MH/SA spending per user $796 $888 $1,111 $1,219 53.1%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 6.80%
(6.51%, 7.15%
8.56%
(8.24%, 8.98%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 9.40%
(9.04%, 9.77%)
11.55%
(11.15%, 11.94%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.39%a
(-0.85%, 0.09%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$174.04
(-$258.15, -$89.94)
  1. Not significant at p<0.05.

Row 2 shows the results for the FFS-NAT’s comparison plan. For the comparison plan, the probability of any MH/SA use in the pre-parity period was 8.9% in 1999 and 10.0% in 2000 (Column 1), and in the post-parity period it was 11.0% in 2001 and 12.3% in 2002 (Column 2). The change in probability of child MH/SA use from pre- to post-parity was 38.2% for the FFS-NAT’s comparison plan (Column 3).

Rows 3 and 4 of Table IV.K.1 show actual MH/SA spending for children per enrollee in FFS-NAT. Row 3 shows spending per enrollee pre-parity in FFS-NAT was $44 in 1999 and $55 in 2000 (Column 1), and post-parity it was $71 in 2001 and $87 in 2002 (Column 2). The change in spending per enrollee from pre-to post-parity (1999 to 2002) was 97.7% for the FFS-NAT plan, as shown in Column 3.

Row 4 shows the same spending results per enrollee for the comparison plan: spending per enrollee pre-parity was $71 in 1999 and $88 in 2000 (Column 1), and post-parity it was $122 in 2000 and $150 in 2001 (Column 2). The change in spending per enrollee from pre- to post-parity (1999 to 2002) was 111.3% for the comparison plan, as shown in Column 3.

Rows 5 and 6 show actual MH/SA spending for children per user. For the FFS-NAT plan, shown in Row 5, spending per user pre-parity was $674 in 1999 and $773 in 2000 (Column 1), and post-parity it was $883 in 2001 and $988 in 2002 (Column 2). The change in spending per user from pre- to post-parity (1999 to 2002) was 46.6% for the FFS-NAT plan, as shown in Column 3.

Row 6 shows the same spending results per user for the comparison plan: spending per user pre-parity was $796 in 1999 and $888 in 2000 (Column 1), and post-parity it was $1,111 in 2001 and $1,219 in 2002 (Column 2). The change in spending per user from pre- to post-parity was (1999 to 2002) 53.1% for the comparison plan, as shown in Column 3.

Panel 2 contains Rows 7 and 8, which show the average expected probability of any child MH/SA use (expressed as estimated percentages of the continuously enrolled child population) and 95% confidence intervals for these estimates for both the FFS-NAT plan and its comparison plan, respectively. For the FFS-NAT plan, 6.8% of continuously enrolled children were estimated to use MH/SA services in the 1999 to 2000 pre-parity period, compared to 8.6% in the 2001 to 2002 post-parity period. For the comparison plan, the corresponding percentages were 9.4% in the pre-parity period and 11.5% in the post-parity period.

Panel 3 shows the difference-in-differences estimates and their 95% confidence intervals for children’s use of any MH/SA services and conditional spending. Row 9 of Panel 3 reports the difference-in-differences estimated impact of the parity policy on MH/SA service use for children as -0.39 percentage points, which was calculated using the same (C-A) – (B-D) difference-in-differences formula as described previously for the adult MH/SA use and spending difference-in-differences analysis. This estimate also appears in Row 1, Column 2 of Table IV.K.0. The estimated 95% confidence interval for the -0.39 percentage point estimate use contained zero (as shown in Row 9 of Table IV.K.1). Thus, the estimated impact of parity on children’s MH/SA was not significantly different from zero at the 5% probability level.

Row 10 reports the difference-in-differences estimated impact of the parity policy on MH/SA spending for children conditional on MH/SA services use. For the FFS-NAT plan, the estimated impact of parity on MH/SA spending was -$174.04, which is also shown in Row 1, Column 3 of summary Table IV.K.0. As the confidence interval did not contain zero, the estimated $174.04 decrease in spending on MH/SA services for children in the FFS-NAT plan was significantly different from zero at the 5% probability level.

As reported previously in the implementation analysis in chapter III, implementing parity coincided with introducing a managed behavioral health care carve-out program in the FFS-NAT plan. Thus, the FFS-NAT difference-in-differences estimate captures the impact of both the new managed care arrangement and the parity policy.

Findings Across Plans

Table IV.K.0 summarizes the results of the difference-in-differences estimates of the impact of parity on child MH/SA use (Column 2) and conditional spending (Column 3) for children in the nine selected FEHB plans. As Column 2 shows, a positive and significant effect of parity (at p<0.05) on the probability of children’s MH/SA use was observed only for the FFS-MA2 plan, in which a 0.73 percentage point increase in MH/SA use was estimated.

For seven of the nine FEHB plans, the estimated impact of parity on the probability of MH/SA use was not significantly different from zero at the 5% probability level, while in one plan, it was significant but negative, i.e., the 1.51 percentage point decrease for HMO-NE. Thus, while the before-after-parity analysis found an increase in the rate of MH/SA services use when comparing the 1999 to 2000 pre-parity period to the 2001 to 2002 post-parity period, the difference-in-differences results for the same time periods found little evidence of a post-parity increase in MH/SA service use relative to the secular trend.

Column 3 of Table IV.K.0 summarizes the difference-in-differences estimates of the impact of parity on child MH/SA spending conditional on MH/SA service use. Four plans -- FFS-NAT, FFS-S, HMO-W1, and HMO-NE -- all had negative impact estimates (i.e., decreases in spending from pre- to post-parity) that were significantly different from zero at the 5% probability level. The magnitude of these estimated spending decreases ranged from $174.04 for FFS-NAT to $320.00 for FFS-W. As noted above, the FFS-NAT plan had introduced a behavioral health carve-out program at the same time the parity policy was implemented. HMO-W1, HMO-NE, and FFS-S already had managed behavioral health care initiatives in place before implementing the parity policy.

The spending impact estimates for four of the other five FEHB plans were also negative but not significantly different from zero. Only one of the nine plans, FFS-NE1, had a positive (although insignificant) impact estimate, i.e., none showed increases in spending greater than the secular trend attributable to the parity policy.

Discussion

The implementation of parity itself resulted in little or no increase in MH/SA service use or spending for children. As was the care for adults, children’s patterns of utilization were governed by the same parity policy and managed care arrangements.

While the before-after-parity analysis found an increase in the rate of child MH/SA services use from pre- to post-parity, the difference-in-differences analysis, which takes into account the influence of secular trends, revealed that the observed increase in use over the same time period was primarily due to a general trend in increased MH/SA service use for children. Only FFS-S experienced an actual decline in MH/SA spending for children in the year after parity was implemented, from $859 in 1999 and $942 in 2000 (pre-parity) to $898 in 2001 and $1,009 in 2002 (post-parity).

The difference-in-differences estimates for the impact of parity on MH/SA spending for children conditional on any MH/SA use offered no evidence of increases in spending attributable to the parity policy. While the plan-specific results (Tables IV.K.1 through IV.K.9) showed growth in MH/SA spending per user for children over the four years observed, spending also grew for children in the comparison plans over the same time period.

These difference-in-differences results confirm that MH/SA spending growth for children in the nine selected FEHB plans was on par with or below that in other large privately insured populations. Thus, these results are “negative” in terms of the impact of parity for children (as was the case in the difference-in-differences results reported earlier for adults), i.e., the parity policy had little impact on child MH/SA service use or spending.

Table IV.K.2. FFS-MA1 Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 9.7% 10.6% 12.3% 13.4% 38.1%
2 Comparison plan actual probability of MH/SA use 7.5% 8.8% 9.7% 11.2% 49.3%
3 Actual MH/SA spending per enrollee $102 $128 $167 $183 79.4%
4 Comparison plan actual MH/SA spending per enrollee $61 $82 $118 $133 118.0%
5 Actual MH/SA spending per user $1,057 $1,205 $1,360 $1,360 28.7%
6 Comparison plan actual MH/SA spending per user $813 $930 $1,213 $1,193 46.7%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 10.21%
(9.83%, 10.60%)
12.99%
(12.57%, 13.42%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 8.20%
(7.55%, 8.88%)
10.50%
(9.70%, 11.25%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity 0.48%a
(-0.27%, 1.17%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$48.47a
(-$337.61, $240.67)
  1. Not significant at p<0.05.

 

Table IV.K.3. FFS-MA2 Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 9.5% 10.5% 12.3% 13.8% 45.3%
2 Comparison plan actual probability of MH/SA use 7.5% 8.8% 9.7% 11.2% 49.3%
3 Actual MH/SA spending per enrollee $67 $83 $112 $138 106.0%
4 Comparison plan actual MH/SA spending per enrollee $61 $82 $118 $133 118.0%
5 Actual MH/SA spending per user $699 $793 $914 $1,003 43.5%
6 Comparison plan actual MH/SA spending per user $813 $930 $1,213 $1,193 46.7%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 9.98%
(9.62%, 10.36%)
13.02%
(12.61%, 13.48%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 8.17%
(7.54%, 8.82%)
10.49%
(9.71%, 11.23%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity 0.73%
(0.01%, 1.46%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$79.22a
(-$358.11, $199.66)
  1. Not significant at p<0.05.

 

Table IV.K.4. FFS-NE1 Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 5.2% 5.7% 7.0% 8.5% 63.5%
2 Comparison plan actual probability of MH/SA use 7.5% 8.8% 9.7% 11.2% 49.3%
3 Actual MH/SA spending per enrollee $40 $50 $72 $107 167.5%
4 Comparison plan actual MH/SA spending per enrollee $61 $82 $118 $133 118.0%
5 Actual MH/SA spending per user $782 $872 $1,031 $1,263 61.5%
6 Comparison plan actual MH/SA spending per user $813 $930 $1,213 $1,193 46.7%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 5.46%
(5.15%, 5.80%)
7.74%
(7.35%, 8.15%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 8.16%
(7.48%, 8.90%)
10.48%
(9.73%, 11.28%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.03%a
(-0.77%, 0.70%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity $20.36a
-$284.07, $324.80)
  1. Not significant at p<0.05.

 

Table IV.K.5. FFS-NE2 Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 5.8% 7.3% 8.3% 9.3% 60.3%
2 Comparison plan actual probability of MH/SA use 7.5% 8.8% 9.7% 11.2% 49.3%
3 Actual MH/SA spending per enrollee $57 $88 $102 $131 129.8%
4 Comparison plan actual MH/SA spending per enrollee $61 $82 $118 $133 118.0%
5 Actual MH/SA spending per user $983 $1,203 $1,232 $1,404 42.8%
6 Comparison plan actual MH/SA spending per user $813 $930 $1,213 $1,193 46.7%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 6.59%
(6.10%, 7.05%)
8.86%
(8.32%, 9.44%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 8.18%
(7.44%, 8.88%)
10.48%
(9.72%, 11.29%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.04%a
(-0.92%, 0.80%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$128.84a
(-$458.65, $200.96)
  1. Not significant at p<0.05.

 

Table IV.K.6. FFS-W Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 5.7% 6.5% 7.1% 8.2% 43.9%
2 Comparison plan actual probability of MH/SA use 9.4% 10.4% 11.3% 12.2% 29.8%
3 Actual MH/SA spending per enrollee $43 $58 $76 $97 125.6%
4 Comparison plan actual MH/SA spending per enrollee $74 $82 $105 $145 95.9%
5 Actual MH/SA spending per user $754 $885 $1,071 $1,177 56.1%
6 Comparison plan actual MH/SA spending per user $781 $794 $922 $1,195 53.0%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 6.08%
(5.75%, 6.39%)
7.66%
(7.27%, 8.05%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 9.93%
(9.32%, 10.55%)
11.75%
(11.03%, 12.44%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -0.24a
(-0.87%, 0.42%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$103.21a
(-$316.82, $110.39)
  1. Not significant at p<0.05.

 

Table IV.K.7. FFS-S Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 6.8% 7.5% 8.5% 9.7% 42.6%
2 Comparison plan actual probability of MH/SA use 9.4% 10.4% 11.3% 12.2% 29.8%
3 Actual MH/SA spending per enrollee $58 $71 $77 $97 67.2%
4 Comparison plan actual MH/SA spending per enrollee $74 $82 $105 $145 95.9%
5 Actual MH/SA spending per user $859 $942 $898 $1,009 17.5%
6 Comparison plan actual MH/SA spending per user $781 $794 $922 $1,195 53.0%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 7.19%
(6.87%, 7.53%)
9.11%
(8.74%, 9.52%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 9.85%
(9.25%, 10.43%)
11.70%
(10.95%, 12.39%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity 0.06%a
(-0.52%, 0.65%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$320.00
(-$499.54, -$119.35)
  1. Not significant at p<0.05.

 

Table IV.K.8. HMO-W1 Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

 1 Actual probability of MH/SA use 4.8% 5.7% 7.0% 7.6% 58.3%
2 Comparison plan actual probability of MH/SA use 6.1% 7.3% 7.8% 8.8% 44.3%
3 Actual MH/SA spending per enrollee $28 $40 $50 $63 125.0%
4 Comparison plan actual MH/SA spending per enrollee $41 $51 $77 $97 136.6%
5 Actual MH/SA spending per user $598 $711 $713 $834 39.5%
6 Comparison plan actual MH/SA spending per user $668 $701 $981 $1,104 65.3%
P
A
N
E
L

2

7 Average expected probability of MH/SA use pre- to post-parity 5.21%
(4.72%, 5.68%)
7.31%
(6.74%, 7.87%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 6.70%
(6.31%, 7.07%)
8.30%
(7.91%, 8.77%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity 0.50%a
(-0.14%, 1.11%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$293.77
(-$517.11, -$70.43)
  1. Not significant at p<0.05.

 

Table IV.K.9. HMO-NE Child MH/SA Use and Spending -- Difference-in-differences Analysis

  Column 1 Column 2 Column 3
Pre-parity Post-parity Change from pre- to post-parity
1999 2000 2001 2002
P
A
N
E
L

1

1 Actual probability of MH/SA use 5.1% 5.2% 5.7% 6.2% 21.6%
2 Comparison plan actual probability of MH/SA use 6.6% 7.5% 8.7% 10.0% 51.5%
3 Actual MH/SA spending per enrollee $28 $38 $55 $65 132.1%
4 Comparison plan actual MH/SA spending per enrollee $52 $63 $99 $123 136.5%
5 Actual MH/SA spending per user $563 $722 $960 $1,054 87.2%
6 Comparison plan actual MH/SA spending per user $789 $845 $1,129 $1,229 55.8%
P
A
N
E
L

7 Average expected probability of MH/SA use pre- to post-parity 5.15%
(4.84%, 5.47%)
5.95%
(5.60%, 6.29%)
 
8 Comparison plan average expected probability of MH/SA use pre- and post-parity 7.12%
(6.89%, 7.37%)
9.42%
(9.17%, 9.71%)
P
A
N
E
L

3

9 Difference-in-differences in probability of MH/SA use from pre- to post-parity -1.51%
(-2.00%, -1.00%)
 
10 Difference-in-differences estimate of MH/SA spending per user from pre- to post-parity -$307.22
(-$632.98, -$18.54)

 

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