We used Medicaid Analytic Extract (MAX) files from calendar year 2007. The MAX files contain all inpatient (IP), outpatient, and pharmacy claims for Medicaid beneficiaries from each state and the District of Columbia. We investigated the service use of adult beneficiaries (ages 18-64) diagnosed with schizophrenia or bipolar disorder who were eligible for full Medicaid benefits on the basis of disability for at least 10 months in 2007, and who were not enrolled in any other sources of coverage--including Medicare. The analysis only included states that submitted complete fee-for-service (FFS) or managed care encounter claims in 2007. Twenty-two states had data sufficiently complete and reliable to include: Alabama, Alaska, California, Connecticut, the District of Columbia, Georgia, Idaho, Illinois, Indiana, Iowa, Louisiana, Maryland, Mississippi, Missouri, Nevada, New Hampshire, North Carolina, North Dakota, Oklahoma, South Dakota, West Virginia, and Wyoming.
The most significant data issue limiting the number of states in the analysis was missing or poor quality encounter data in states that used managed care to deliver services to disabled beneficiaries. Nearly two-thirds of the 29 states excluded from the study were dropped due to missing or unreliable encounter data. As of the time the 2007 MAX files were created, encounter claims were not subject the same validation process for completeness or reliability as FFS claims routinely undergo and the Centers for Medicare and Medicaid Services (CMS) did not recommend using these data for analysis. Nevertheless, a number of states reported encounter data that appeared to be complete and reliable in 2007, including at least one state (Iowa) that relied on managed care to deliver specialty mental health services. In six of the 22 states in the study, beneficiaries enrolled in some form of managed care were included in the analysis.
In comparison, relatively few states were excluded from the analysis due to problems in the completeness or reliability of FFS claims data. When states were excluded for problems with their FFS data, it was often the case that entire data files were missing or that mental health services specifically were missing due to special delivery and billing arrangements between Medicaid and other state agencies.1 Additionally, a number of states were excluded from the study due to unreliable identification of beneficiaries enrolled in managed care or private insurance on the enrollment file.2
The final analytic file included 143,710 beneficiaries. Based on the most frequent primary diagnosis during the year, 102,884 beneficiaries had a primary diagnosis of schizophrenia and 40,609 had a primary diagnosis of bipolar disorder.3 More information about the data and methodology used for the study, including specifications of our measures of EBPs, is included in the technical appendix at the end of this report. Given the limitations of using one calendar year of claims data, we did not seek to measure EBPs in terms of adherence to a strict clinical guideline or the degree to which a certain EBP was implemented with fidelity. Rather, we sought to measure whether beneficiaries received a minimal standard of care that is consistent with the evidence and measureable in claims data.