Appendix B: Medical Expenditure Panel Survey (MEPS)
National Healthcare Disparities Report, 2008
Medical Expenditure Panel Survey (MEPS)
The Medical Expenditure Panel Survey (MEPS) is designed to provide nationally representative estimates of health care use, expenditures, sources of payment, insurance coverage, and adult disability status as measured by activity limitations for the U.S. civilian noninstitutionalized population. MEPS is cosponsored by the Agency for Healthcare Research and Quality (AHRQ) and the National Center for Health Statistics (NCHS). MEPS comprises three component surveys: the Household Component (HC), the Medical Provider Component (MPC), and the Insurance Component (IC). The HC is the core survey of MEPS.
The MEPS HC, a nationally representative survey of the U.S. civilian noninstitutionalized population, collects medical expenditure data at both the person and household levels. The HC collects detailed data on demographic characteristics, health conditions, health status, use of medical care services, charges and payments, access to care, satisfaction with care, health insurance coverage, income, and employment.
The HC uses an overlapping panel design in which data are collected through a preliminary contact followed by a series of five rounds of interviews over a 2½-year period. Using computer-assisted personal interviewing (CAPI) technology, data on medical expenditures and use for 2 calendar years are collected from each household. This series of data collection rounds is launched each year on a new sample of households to provide overlapping panels of survey data and, when combined with other ongoing panels, will provide continuous and current estimates of health care expenditures.
The sample of households selected for the MEPS HC is drawn from respondents to the National Health Interview Survey (NHIS), conducted by NCHS. The NHIS provides a nationally representative sample of the U.S. civilian noninstitutionalized population, with oversampling of Hispanics and Blacks.
For more detailed information about the MEPS and the information discussion here, please see the documentation for the MEPS 2005 Full Year Consolidated Data File available at the MEPS Web site (http://meps.ahrq.gov).
National health care estimates from MEPS for the 2008 NHQR and NHDR were derived from the 2005 MEPS HC survey, including the Self-Administered Questionnaire (SAQ), the Child Health and Preventive Care section, and the Diabetes Care Survey (DCS).
The SAQ was a supplement to the MEPS HC and was completed in late 2005 and early 2006 (Panel 9 Round 4 and Panel 10 Round 2). It included health care quality measures taken from the health plan version of CAHPS®, an AHRQ-sponsored family of survey instruments designed to measure quality of care from the consumer's perspective; general health questions; attitudes about health questions; and health status questions as measured by the SF-12 and the EuroQol 5D.
The Child Health and Preventive Care section was part of the regular MEPS HC interview that, like the SAQ, took place in late 2005 and early 2006 (Panel 9 Round 4 and Panel 10 Round 2). It included health care quality measures taken from the health plan version of CAHPS®; the Children With Special Health Care Needs (CSHCN) Screener questions; children's general health status as measured by several questions from the General Health Subscale of the Child Health Questionnaire; Columbia Impairment Scale questions about possible child behavioral problems; and child preventive care questions. Researchers should note that the CAHPS® and CSHCN questions changed from a self-administered parent questionnaire in 2000 to an interviewer-administered questionnaire starting in 2001.
A third supplement to the MEPS HC, the Diabetes Care Survey (DCS), was a self-administered questionnaire given to people identified with diabetes. It asked about the care they received in the treatment of their diabetes.
For analytical variables asked at specific rounds, age and other population characteristics variables were also defined using the round-specific variables. Where available, missing values were replaced with the value from the closest prior round.
Estimates derived from MEPS are presented at both an aggregate level and for select subpopulations. Characteristics used to define subpopulations included age, gender, race, ethnicity, poverty status, education, insurance coverage, proximity to metropolitan areas, preferred language at home, employment status, perceived health status, children with special health care needs, and adult disability status as measured by activity limitations. A brief description of how each of these population characteristics was defined is provided below.
Age—With the exception of analytic variables associated with round-specific questions noted below, age was defined as a person's age on December 31 of the data year.
For measures using analytic variables associated with round-specific questions (e.g. questions from the SAQ, the Child Health and Preventive Care supplement, as well as access-to-care measures), corresponding round-specific age variables were used to determine age.
Gender—Male and female.
Race—Variable RACEX classifies persons into five single race categories (1-5) and one for multiple races. For all tables, RACEX was used and reordered as: (1) White, (2) Black, (3) Asian, (4) Native Hawaiian or Other Pacific Islander, (5) American Indian or Alaska Native, (6) multiple races. The race groups in the 2000 and 2001 tables include persons of Hispanic and non-Hispanic origin. From 2002, MEPS has transitioned to the most recent Office of Management and Budget standards issued in 1997 for collecting racial and ethnic data, which allows respondents to identify more than one racial/ethnic group. Therefore, estimates for racial categories using 2002 and later years' data are not directly comparable with estimates from previous years' data.
Ethnicity—Ethnicity was determined to be either Hispanic or non-Hispanic. Persons of Hispanic origin may be of any race. Estimates were derived for both Hispanic and non-Hispanic subpopulations. In addition, race was crossed with ethnicity and estimates were reported for persons classified as "non-Hispanic, White," "non-Hispanic, Black," and "non-Hispanic, other." For 2002 and later years, "non-Hispanic, White" and "non-Hispanic, Black" categories excluded multiple-race individuals and estimates are not directly comparable with data from previous years.
Poverty status—MEPS includes a five-level categorical variable for family income as a percentage of the Federal poverty threshold. For construction of this variable, definitions of income, family, and poverty are taken from the poverty statistics developed by the Current Population Survey (CPS). For the purposes of analysis and reporting in the NHDR, the near-poor and low-income categories were combined. This resulted in a four-level categorical variable of poverty status: (1) negative or poor refers to household incomes below the Federal poverty line; (2) near poor/low income, from the poverty line to just below 200% of the poverty line; (3) middle income, 200% to just below 400% of the poverty line; and (4) high income, 400% or more of the poverty line. Beginning with the 2002 file, there were substantial revisions made to the skip patterns in the Income section. These changes have increased response rates, resulting in a small impact on income estimates for persons under age 65, with a somewhat larger impact on persons age 65 and over.
Education—In MEPS, a person's educational attainment is indicated as the number of completed years of education. For the NHQR/NHDR, this continuous measure was grouped into three categories: (1) less than high school refers to persons with less than 12 completed years of education; (2) high school graduate, persons with exactly 12 completed years of education; and (3) at least some college, persons with greater than 12 completed years of education. This variable was constructed only for persons age 18 years and over and any measure presented for the education subpopulations includes only persons in this age group.
Insurance coverage—The insurance coverage variable was constructed in a hierarchical manner and in relation to a person's age. For persons under age 65, those who were uninsured for the entire year were classified as uninsured; those who had private coverage at any time during the year (including CHAMPUS/VA) were classified as having had private insurance; and those who had only public coverage (i.e., no private) at any time during the year were classified as public only. Persons over age 65 were categorized as having Medicare only, Medicare and private, or Medicare and other public assistance. A small number of persons were identified as not having Medicare or other private or public assistance. These people were not included in insurance-related analyses.
Residence location—For the 2008 NHDR and NHQR, the 2006 NCHS Urban-Rural Classification Scheme for Counties was used. NCHS based this classification scheme for counties on: the Office of Management and Budget (OMB) definitions of metropolitan and nonmetropolitan counties; the Rural-Urban Continuum Codes and the Urban Influence Codes developed by the Economic Research Service of the U.S. Department of Agriculture; and county-level data from the Census 2000 and 2004 postcensal population estimates. Based on this scheme, the urban-rural categories used in the 2008 NHQR/NHDR are as follows: (1) large central metro ("central" counties of metropolitan areas of 1 million or more population); (2) large fringe metro ("fringe" counties of metropolitan areas of 1 million or more population); (3) medium metro (counties in metropolitan areas of 250,000 to 999,999 population); (4) small metro (counties in metropolitan areas of 50,000 to 249,999 population); (5) micropolitan (counties adjacent to metro area, with at least one urban cluster of at least 10,000 residents); and (6) noncore (counties without an urban cluster of at least 10,000 residents).
The two nonmetropolitan levels of the NCHS classification, micropolitan and noncore, are derived directly from the differentiation of nonmetropolitan territory specified in the 2003 OMB standards for defining metropolitan and micropolitan counties. For more information, visit http://www.cdc.gov/nchs/r&d/rdc_urbanrural.htm.
Employment status—MEPS includes four-level round-specific categorical variables for employment status for persons age 16 and over. For the MEPS tables, employment status variables were set for adults ages 18-64. Employed included levels 1-3, e.g., adults who were currently employed, had a job to return to, or had a job but did not work during the reference period. Unemployed included those who were unemployed during the reference period.
Perceived health status—MEPS includes five-level round-specific categorical variables for perceived health status: excellent; very good; good; fair; and poor. For the tables, the five levels were collapsed into two levels: excellent/very good/good; and fair/poor.
Children with special health care needs—The variable CSHCN42 identifies children with special health care needs based on the CSHCN Screener instrument developed through a national collaborative process as part of the Child and Adolescent Health Measurement Initiative (CAHMI) under the coordination of the Foundation for Accountability. Missing values (CSHCN42=3) were excluded.
Preferred language at home—For each individual family member, the Access to Care section ascertained what language the person prefers to speak at home (LANGHM42), with the categories English, Spanish, and Other. Persons who prefer to speak Spanish or a language other than English (LANGHM42 = 2 or 3) were combined as "Other."
Adult disability status as measured by activity limitations—The measure used in the NHQR/NHDR for MEPS is based on the work of an interagency workgroup that was instituted to provide a measure of disability as consistent and compatible as possible across all the data sets used for this publication. For the purpose of the NHQR/NHDR, adults with disability are defined to be those with a physical, sensory, and/or mental health conditions that can be associated with a decrease in functioning in such day-to-day activities as bathing, walking, doing everyday chores, and/or engaging in work or social activities. The workgroup recommended using paired measures in displaying disability data for adults to preserve the qualitative aspects of the data. The first measure, Limitations in basic activities, represents problems with mobility and other basic functioning at the person level. The second measure, Limitations in complex activities, represents limitations encountered when the person, in interaction with his or her environment, attempts to participate in community life. Basic activities include problems with: mobility; self-care (activities of daily living); and domestic life (instrumental activities of daily living); and activities dependent on sensory functioning (limited to persons who are blind or deaf). Complex activities include limitations experienced in work and in community, social, and civic life. These two categories are not mutually exclusive since persons may have limitations both in basic activities and in complex activities. The residual category Neither includes adults with neither basic nor complex activity limitations.
Standard errors of the estimates were provided to permit an assessment of the sampling variability. All estimates and standard errors were derived using SUDAAN statistical software which accounts for the complex survey design of MEPS.
All estimated proportions and ratios are weighted to reflect the experiences of the U.S. civilian noninstitutionalized population at the aggregate and subpopulation levels. For example, the SAQ person-level weight (SAQWT05F) was used for measures from the SAQ, and the diabetes person-level weight (DIABW05F) was used for measures from the Diabetes Care Survey. For other person-level measures, including those from the Child Health and Preventive Care section, the overall person-level weight (PERWT05F) was used. For the Child Health and Preventive Care measures, child population included children (under 18) with a positive person-level weight who had been asked these questions during the later half of 2005 (where PERWT05F>0 and PSTATS42 was not equal to 31 (deceased)).
Tables containing estimates from MEPS are included in . Consistent with the established criteria for data reporting in the NHDR and NHQR, MEPS estimates are suppressed when they are based on sample sizes of fewer than 100, or when their relative standard errors are 30% or more. In the tables, these data are replaced with symbols to indicate that data are statistically unreliable. Records in which analytic variables have missing values were excluded for analysis.
For further information, go to the MEPS Web site: http://meps.ahrq.gov.