Many existing national surveys collect disability-related information, and some do so in great detail. There is substantial variation across surveys in terms of target populations, the disability measures used, topics covered, frequency, and design. We provide an overview of the 40 national, federally-sponsored surveys we reviewed for this study, focusing on the disability-related content. While numerous data sources provide information about people with disabilities, no single source provides comprehensive data on all issues of interest to ASPE. Our review is intended to illustrate the kinds of information available and the variation across existing survey data sources to provide a context for considering options designed to improve disability data. A list of the surveys reviewed is shown in Table II.1. A tabular summary of the features of the 40 surveys is presented in Appendix B. Detailed summaries of each survey are provided in a companion report (Livermore et al. 2011b).
|TABLE II.1. Surveys Reviewed|
|National Household Surveys|
|Surveys on Health, Disability, Aging, and Long-Term Care|
|Surveys on Youth, Education, and Transition|
We identified several additional surveys that we did not review but which met the criteria for inclusion in our review described in Chapter I and/or were identified as being used by the federal and state staff that provided input to this study.2
In what follows, we provide a summary of the 40 surveys reviewed for this study, focusing on the population coverage and frequency of administration, disability-related content, the inclusion of longitudinal data, and links between the surveys and administrative data sources. The final two sections describe several new survey efforts and provide some general observations about the nature and content of the 40 surveys, respectively.
1. Coverage and Frequency
a. Ongoing National Household Surveys
The 17 surveys in this group are representative of all or most of the United States population. These surveys are conducted on a regular basis and represent the core of the governments national data collection efforts to monitor the characteristics, health, and well-being of the United States population.
Most ongoing national surveys cover the household or noninstitutional population, though the ACS (since 2006), AHS, Census, and the 1996 MEPS also cover certain nonhouseholdor group quarters populations. The nonhouseholdpopulation is important to consider with respect to disability data because people with disabilities are disproportionally represented in this group (She and Stapleton 2009). Most ongoing national surveys include individuals of all ages in their samples, but in many cases a single household member provides information on all other family members, and in several instances children under a particular age are excluded.
Surveys in this category are fielded regularly, some annually and others less frequently (for example, every 4-8 years). Most have data available from 2007 or later. All but one (the PSID) can generate time-series data. About half of these surveys support estimates at regional or state levels.
b. Surveys on Health, Disability, Aging, and Long-Term Care
The surveys in this group are generally conducted less frequently than the ongoing national surveys described above. However, with the exception of the NHIS-D, which was only conducted in 1994-1996, and the LSOA, which was last conducted in 2000, data are available from multiple sources on this topic for calendar years 2004 and later. Seven of the 11 surveys produce time-series data and six of them support regional or state-level estimates.
The HRS, LSOA, and NLTCS are longitudinal studies that examine changes as individuals age. The HRS targets people over age 50 and follows them based on their birth cohort. Two LSOA studies followed individuals age 55 or older from the 1984 and 1994 NHIS samples until 1990 and 2000, respectively. The NLTCS used a sample of individuals ages 65 and older drawn from Medicare eligibility files in 1982 and followed them until 2004.
In addition to the NLTCS, several other surveys derive their samples from program participation populations. The MCBS draws its sample from Medicare beneficiaries, the HOS from Medicare Advantage enrollees, the NBS from Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) beneficiaries, and the NSCF from children receiving SSI benefits. Though not specifically a program participant sample, the NNHS derives its sample from nursing home residents, many of whom are Medicaid and Medicare beneficiaries.
The NHIS-D and NS-CSHCN screened respondents based on their own and/or their childs health and disability status. The first Phase of the NHIS-D was a supplement to the NHIS, administered to all respondents in 1994 and 1995. If individuals were identified as having or potentially having a disability, they were screened into Phase II, which collected more detailed information related to disability. The NS-CSHCN similarly asked questions of a nationally representative sample of children in households. Another general population survey that screened for particular health conditions is the NCS. The NCS screened respondents for a variety of mental health disorders based on a lengthy questionnaire.
c. Surveys on Youth and Education
All of the surveys in this group restrict their samples to particular age groups, and many focus on even more specific target populations. For example, the B&B and BPS sampled those graduating from and beginning postsecondary education, and the HSLS sampled only students enrolled in the 9th grade. Nearly all have been fielded relatively recently; with the exception of the NELS, which was last fielded in 2000, data are available from 2007 or later. Three of the nine surveys in this category can produce estimates at the state or regional level.
Most of the surveys in this category are sponsored by the Institute of Education Sciences (IES) in the U.S. Department of Education and are longitudinal in nature, to track how children and young adults develop over time and to relate experiences to outcomes. The major differences across the IES surveys are the age groups and populations of interest. The B&B focuses on college graduates, BPS on college freshmen, HSLS on those enrolled in 9thgrade, NELS on those enrolled in 8th grade, and ECLS on young children, sampled at nine months or at kindergarten enrollment. Somewhat different from the other IES studies, the NLTS2 followed secondary students who were receiving special education services as they moved into adult roles. Though not sponsored by IES, the NLSY97 used a similar age cohort--youth ages 12-16--and followed transitions to adult outcomes that were similar to the NLTS2.
Add Health and the NSCH are focused on issues of health and health care. Add Health sampled adolescents enrolled in grades 7-12 and collected information on how social and behavioral factors influence health over time. The NSCH sampled children under age 18.
d. Other Surveys
The three surveys in this group address specific agency needs and are useful primarily for research about their specific target populations, which are generally not addressed in other surveys. They are conducted relatively infrequently and none of them support state or regional estimates.
The NSV is focused on collecting information for developing and evaluating U.S. Department of Veterans Affairs (VA) programs. It uses a sample of veterans and, starting in 2009, active members of the military as well as their families. The SILJ and SISCF/SIFCF are nearly identical surveys that collect information on inmates in local jails and prisons, respectively, in order to evaluate the needs of the incarcerated population and remedy deficiencies in correctional institutions.
2. Disability-Related Content
a. Ongoing National Household Surveys
With a few exceptions, the ongoing national household surveys collect information that permits users to identify people with disabilities. However, the level of detail available in the identifying questions and the amount of other disability-related topical information contained in these surveys varies. Information on program participation, education, and employment appears in nearly all of the ongoing national surveys. Relatively few, however, provide detailed information on learning disability, social participation, transportation, environmental barriers, accommodations, and whether the respondents are considered by themselves or others to have a disability.
The ACS, AHS, and CPS use a common set of six questions to identify hearing impairments, vision impairments, physical disabilities, mental disabilities, self-care disabilities, and independent living limitations. These questions were added to the AHS in 2009 and to the CPS in 2008. As a result, the surveys can now be used to compare the population with disabilities with the rest of the population, or those with one category of disability against those with another. However, they do not allow for descriptions of disabilities or limitations, or for certain distinctions, such as whether a limitation in decision making is due to cognitive impairment, a developmental disability, or mental health. Also, because these questions were recently added, they can only be used to track short-term trends.
The BRFSS, MEPS, NHANES, NHIS, PSID, and SIPP contain a substantial amount of information on health and disability, but even among these surveys the level of detail varies considerably. Some, like the BRFSS, collect relatively basic information on issues relevant to disability, such as functional limitations, use of special equipment, and need for assistance or care. At the other end of the spectrum, the SIPP and the NHIS contain a wider variety of measures of health status and disability.
The CE and SCF are two surveys in this group with very little disability-related information. These surveys collect disability information only in the context of income and expenditures. In both cases, respondents are asked about disability income (for example, SSDI, SSI, workers compensation, and veterans compensation). In the CE, respondents are also asked about medical expenditures; in both surveys, respondents can indicate disability as a reason for not working (if they indicate they are not working), but in neither survey are all respondents directly queried about their disability status. While these surveys can be used to identify the population with a disability that prevents work or with expenditures on given services or devices associated with certain limitations or conditions, their utility for disability research is limited due to their lack of disability indicators. The ATUS has a similar issue; however, its sample is derived from the CPS and so it is possible to match responses to the new CPS disability questions to the ATUS sample. As of 2010, the Census no longer collects information on disability; the ACS is intended to provide the information to replace disability and other questions previously included on the Census long form.
Other surveys in this group collect information on a particular category of disability, or disability information only from some respondents. The NHES collects information about disabilities that might affect respondents education. Questions address whether they have a disability that affects their ability to learn, or have ever needed or used specialized services. The NSDUH solicits information on issues of mental health, particularly substance abuse, but does not address any other types of disabilities. The NSFH focuses on relationship dynamics among family members, so questions on disability address needs for care and assistance, care provided by family members, symptoms of depression, and drug and alcohol abuse. The NCVS asks detailed questions about disability, but only if the respondent has been the target of a crime during the reference period.
b. Surveys on Health, Disability, Aging, and Long-Term Care
Because they are specifically designed to provide information related to disability and health, the 11 surveys we reviewed in this group include more extensive information on disability than most national household surveys. All include information on physical and functional limitations, limitations in activities of daily living (ADLs), cognitive impairment or developmental disorders, specific conditions, health, and health insurance. Less common topics include substance use, abuse, and dependence (three surveys); bed days (three surveys); learning disabilities (two surveys); and whether the respondents are considered by themselves or others to have a disability (one survey).
A variety of disability-related topic areas are covered in surveys focused on aging. In the HRS, details are collected on disabilities and limitations experienced before age 16, those present at the time of interview, and the impact of disability and aging on work activity. The LSOA focused on physical and cognitive impairments and how respondents cope with challenges as they age. The NLTCS focused on the factors that cause individuals to move from community settings into long-term care facilities, including health, functional status, medical expenditures, and sources of care from family members and others in the community.
The MCBS, HOS, NBS, NSCF, and NNHS include detailed questions about disability targeted to the populations surveyed, and most have links to administrative records from the relevant program. For example, the NBS includes questions about job accommodations, barriers to work and use of U.S. Social Security Administration (SSA) work incentives, and the NSCF focuses on the services needed and used by children who qualify for SSI. Information from the NNHS provides a picture of the needs and characteristics of nursing home residents.
For those screened to participate, the NHIS-D, NS-CSHCN, and NCS collected detailed disability-related information on participants. Phase II of the NHIS-D asked participants to report on particular limitations, their severity, and their effects. The NS-CSHCN collected additional information on those who have more or different medical needs than most children their age for those screened into the sample. The NCS asks a detailed battery of questions related to psychiatric and physical disabilities.
c. Surveys on Youth, Education, and Transition
Information on physical and functional limitations, mental and emotional disorders or symptoms, and employment appear in each of the nine surveys we reviewed that were focused on youth and education. Seven of the nine surveys collect information about learning disabilities, which is relatively uncommon in surveys of other populations. None of these surveys collects information on disability-related expenditures and only two cover issues related to substance use, abuse, and dependence, or transportation.
Disability content in the B&B, BPS, HSLS, NELS, and ECLS focuses on the services children and youth need and receive in school and on the effect of childhood disability on adult outcomes. The disability content in the NLTS2 is much more extensive than in the other education-focused surveys. It includes information on limitations, as well as on services and accommodations provided by school, work, and other sources.
Add Health and NSCH include content related to physical limitations, symptoms of depression and anxiety, and diagnoses. The NSCH provides a general description of childrens health. It includes extensive disability content, including limitations, diagnoses, medications prescribed, and services used, as well as more general questions on health and health care.
d. Other National Surveys
All three surveys in this group include information on sensory and communication limitations, physical and/or functional limitations, mental and emotional disorders or symptoms, specific conditions, disability benefit receipt or program participation, health, use of services related to health and disability, and participation in public programs. Disability information collected by the NSV includes ADL limitations and instrumental activities of daily living (IADL) limitations, as well as VA disability ratings, sources of health insurance, and medical services used. The SILJ and SISCF/SIFCF include detailed sections on drug and alcohol abuse and dependence and on other mental health issues. Some information about physical health and physical limitations is also collected in these surveys. Finally, none of these surveys addresses cognitive impairment or developmental disorders, social participation or interpersonal interaction, use of or need for personal assistance, bed days, household expenses, or transportation.
3. Longitudinal Survey Data
Of the 40 surveys we reviewed, 22 of them are longitudinal or have some longitudinal component. Certain groups have more longitudinal coverage than others; for example there are several longitudinal surveys on youth (Add Health, NLSY), even more specifically focused on students (B&B, ECLS, HSLS, BPS, NELS, NLTS), and several covering older individuals and seniors (HRS, LSOA, NLTCS). Longitudinal surveys focused on subpopulations, such as those receiving Medicare (HOS, MCBS), and on specific topic areas such as health care use (MEPS), crime and victimization (NCVS), and spending habits (CE) also exist. Surveys that address income and economic well-being for the general population, such as the PSID and SIPP, also include extensive longitudinal information.
Of the 22 surveys that contain longitudinal data, seven follow sample members for 1-4 years (B&B, CE, HOS, MEPS, MCBS, NBS, NCVS, SIPP); five follow sample members for roughly 5-10 years (BPS, ECLS, LSOA, NCS, NLTS2), and the remainder contain longitudinal data covering periods of more than 10 years (AHS, HRS, HSLS, NELS, NLTCS, Add Health, NLSY97, NSFH, PSID). Follow-up interviews occur as frequently as quarterly (CE), or as infrequently as a single follow-up interview occurring 10 years after initial interview (NCS).
The AHS, PSID, and HRS are unique in that they have consistently and frequently collected data on sample members for a very long period of time. The AHS follows housing units, rather than individuals, but has followed the same sample of housing units every other year since 1985. Both the PSID and HRS follow individuals from sampling until death, interviewing them every other year--the PSID since 1968 and the HRS since 1992.
4. Administrative Data
Administrative data, alone or linked across programs or with survey data, are an important source of information for addressing disability program and policy issues. Administrative data can address three important limitations of survey data. First, they can often be used to create longitudinal administrative files to assess issues related to the dynamics of disability and program participation over time. Second, administrative data are the best source of information on the participation of people with disabilities in public programs and the characteristics of that participation--information that may be lacking in detail and subject to error in respondent-reported survey data. A final advantage of using administrative data is that they can be collected without posing additional burden on respondents because such efforts make use of data already being collected.
Many of federal and state staff who provided input to this study reported having used administrative data that were linked with survey and/or other administrative data to address disability-related program and policy issues. Linked administrative data also were frequently noted by federal staff as a means for addressing limitations in survey data. In Table II.2 and Table II.3 we list the linkages that were identified by the federal staff who provided input to this study as well as through our review of national surveys. SSA and Centers for Medicare and Medicaid Services (CMS) administrative data appear to be the sources that have been most extensively linked to other data sources, likely due to the importance of the programs operated by these agencies to people with disabilities. SSA data are particularly important for purposes of identifying who among those in a survey sample or other program administrative data are beneficiaries of SSI or SSDI. A number of new administrative data linkages with survey data planned for the near future also are shown in Table II.2, including linkages between national surveys and Medicaid and Medicare Part D administrative data.
Although some of the linkages shown in Table II.2 were conducted for one-time or very specific purposes, many reflect ongoing efforts to link administrative and survey data and make it more widely available for use by researchers. An important example is the National Center for Health Statistics (NCHS) data linkage activities. Under a federal interagency agreement, several NCHS population-based surveys (including the NHANES, NHIS, LSOA, and NNHS) have been linked to data from one or more of the following administrative sources: SSA, Medicare, U.S. Environmental Protection Agency (EPA) air quality, and state mortality data. Because their sampling frames are derived from the NHIS, the MEPS and NHIS-D also can be linked to data from these administrative sources.
|TABLE II.2. Administrative Data Linkages with Survey Data|
|Administrative Data Source||Linkages to Survey Data|
|Financial aid application data from the Central Processing System||B&B, BPS|
|Federal student loan amounts from the National Student Loan Data System||B&B, BPS|
|School records||ECLS, NELS, NLSY97, NLTS2|
|Medicare records from the Inpatient file and Skilled Nursing Facility file||HRS|
|Medicare records from the Denominator file; Medicare Provider Analysis and Review file; the Carrier file; the Home Health Agency file, the Durable Medical Equipment file; the Hospice file and the Outpatient file||HRS, LSOA, MEPS (via NHIS), MCBS, NHANES, NHIS, NHIS-D (via NHIS)|
|Medicare Standard Analytic File||NLTCS|
|Other Health and Medical Data|
|Birth defect data||NS-CSHCN|
|Medicaid Statistical Information System data||ACS, BRFSS|
|EPA air quality data||NHANES, NHIS|
|National Death Index (NDI)||HRS, LSOA, NHANES, NHIS, NNHS|
|U.S. Social Security Administration (SSA)|
|Social Security benefit records: Earnings, Benefits, SSI, Summary of Earnings and Projected Benefits, Wage and Self-Employment Income||HRS|
|Master Beneficiary Record, Supplemental Security Records file, Payment History Update System, 831 Disability Master File, and special extract of summarized quarters of coverage from the Master Earnings File||LSOA, MEPS (via NHIS), NHANES, NHIS, NHIS-D (via NHIS), NNHS|
|SSA data unspecified||CPS, SIPP|
|Area Resource File (county-level records)||MEPS|
|Climate data from nearest climate station||Add Health|
|Census data||Add Health, PSID|
|U.S. Department of Housing and Urban Development (HUD) administrative data||AHS|
|Internal Revenue Service (IRS) data||HRS, SIPP|
|Records from Aid to Families with Dependent Children, food stamps, unemployment, workers compensation, federal civil service retirement, SSI, Social Security and veterans pensions and compensation||SIPP (1984 panel only)|
|Weather data from nearest weather station||Add Health|
|Planned Future Linkages|
|Climate data from nearest climate station||NHIS|
|Medicaid claims data||HRS, LSOA, NHANES, NHIS, NNHS|
|Medicare Part D Denominator File; Medicare Part D Event File; and Chronic Condition Warehouse Summary Files||NHANES, NHIS, NNHS|
|National Highway Planning Network traffic indicators||NHANES|
|National Institute of Diabetes and Digestive and Kidney Diseases information on end-stage renal disease||NHANES, NHIS, NNHS|
|TABLE II.3. Administrative Data Linkages with Other Administrative Data|
|Administrative Data Source||Linkages to Other Administrative Data|
|CMS data unspecified||Area Resource File, Minimum Data Set, Home Health Outcome and Assessment Information Set, Online Survey, Certification and Reporting|
|Rehabilitation Services Administration (RSA-911)||SSA|
|SSA data unspecified||IRS, Medicaid Buy-in program data, RSA-911, multiple SSA administrative data sources in the Ticket Research File, state Workforce Investment Act (WIA) and Wagner Peyser program data, U.S. Department of Defense Retirement data, Veterans program data|
|Veterans Programs||Bureau of Labor Statistics (BLS) unemployment data, SSA|
|State Medicaid Buy-in Programs||SSA|
|State WIA and Wagner Peyser Programs||SSA|
5. New Survey Efforts
While many of the surveys we reviewed continue to collect data, some are undergoing significant changes. Three surveys are adding disability supplements and two are changing the way the survey collects data. In addition, a new survey targeting Medicare beneficiaries over age 65 is in progress. We describe these new efforts below.
a. Modifications to Existing Surveys
In addition to short supplements on disability, which have appeared in various forms since 2008, the 2011 NHIS includes a longer supplement on functioning and disability. The supplement contains questions on the severity of difficulty with particular activities, use of assistive devices (for example, hearing aid, cane), activity limitations, anxiety and depression, and pain. The same questions are being fielded as part of national health surveys in several other countries so that comparisons can be made across countries.
The U.S. Department of Labor (DOL) is in the process of developing a new disability supplement to the 2012 CPS. The focus of the supplement is to provide new, detailed information on the employment-related issues of people with disabilities. Potential topics include the nature of the disability, work history, living arrangements, social environment, family background, income, employment counseling and training, assistive technology and employer accommodations, telecommuting and transportation, and use of government programs. The survey instrument is currently under development and its final contents will reflect input from researchers and disability advocates (DOL 2010).
The SIPP, conducted by the Census Bureau, is in the process of undergoing major changes. The product of these changes, referred to as the Re-Engineered SIPP, will have a new survey design with annual interviews replacing interviews three times a year, and a new survey instrument. SSA is sponsoring a disability supplement to the Re-Engineered SIPP. Detailed information about the contents of the disability supplement is not yet available. SSA is scheduled to deliver the questions for the survey to the Census Bureau in summer 2011.
b. New Data Collection Efforts
The U.S. Department of Education is sponsoring a new round of data collection called the National Longitudinal Transition Survey 2012 (NLTS 2012). The NLTS 2012 will build on the questions included in the NLTS2, but has a more ambitious sample design. The NLTS 2012 sample will contain not only youth identified as needing special education services, but also two other groups: those with a condition that qualifies them for accommodations under Section 504 of the Vocational Rehabilitation Act of 1973 and other students with no identified disability. This will allow the study to gauge how the characteristics, experiences, and outcomes of special education students differ from those of the other two groups of youth. The data collected in the NLTS 2012 will permit comparisons to data in the NLTS2 and NLTS, to examine changes in the characteristics, school experiences, and postsecondary outcomes of special education students.
With funding from the National Institute on Aging (NIA) within the National Institutes of Health, Johns Hopkins Bloomberg School of Public Health and Westat are conducting the National Health and Aging Trends Study (NHATS). The NHATS is a longitudinal survey of Medicare beneficiaries over age 65. The goal of the survey is to monitor changes in daily life and activities throughout the aging process. Participants will be interviewed once a year on topics including living arrangements, economic status and well-being, work status and participation in valued activities, quality of life, daily activities and help provided with such activities, mobility and use of assistive devices, cognitive functioning, health, and health care. During the interview, participants will also be asked to conduct activities including standing, getting up from a chair, walking, breathing, and memory exercises. In addition, the interviewer will record the respondents height, weight, and waist circumference (Center on Population Aging & Health 2010; NHATS 2010).
6. Commentary on Existing Disability-Related Data
Some general observations based on our review of the 40 surveys and the comments on national survey data provided by federal and state agency staff include the following:
The specific measures of disability and wording of questions designed to elicit information about a particular type of disability (for example, visual impairment), differ markedly across surveys. Nearly all of the national surveys reviewed have questions that can be used to identify people with disabilities, but a few, such as the CE, do not.
Based on the state and federal input received, the NHIS and SIPP are the two surveys most frequently used by federal and state staff to address disability-related issues, likely because they contain a relatively large amount of disability content, are representative of the national household population, and include large samples of people with disabilities.
A concerted effort is being made to use a uniform set of disability indicators across surveys. The six-question series included in the ACS, CPS, AHS, and NHIS supplement is part of this effort. A new supplement in the 2011 NHIS, which will include a battery of questions related to disability, represents an effort to make more uniform, descriptive information on disability available across countries.
Few surveys contain measures to specifically identify individuals with cognitive or intellectual disabilities. Measures to identify specific health conditions underlying disability also are uncommon.
There are numerous surveys of specific subpopulations (for example, students, inmates, nursing home residents, and beneficiaries of specific programs) on a variety of disability-related topics. This likely reflects the specific data and information needs of particular agencies and the fact that the general population surveys do not contain large enough samples of individuals in these specific target populations.
Many national surveys have longitudinal components, though most cover a specific subgroup rather than a general population. The PSID and HRS represent the most extensive efforts in that they regularly interview individuals from the time of sampling until death or loss to follow-up.
New disability supplements to the SIPP and CPS will increase the information available on employment, economic well-being, and program participation.
Consumption, expenditures, job accommodations, transportation and means for getting around outside of the home, environmental barriers, and community supports are the general topic areas least commonly addressed for people with disabilities in the surveys we reviewed.
Administrative data have been linked with several of the national surveys. The most frequently linked administrative data sources are from SSA and CMS programs, which have been linked with several health-focused national surveys.
A final important observation is that a considerable amount of survey data is already being collected on disability issues and populations. Finding ways to improve, augment, and coordinate these existing mechanisms is an important means for addressing the limitations of survey data on disability-related issues and populations. We turn to this subject in the next section.