Beauregard et al. (1997) estimated the number of uninsured in the U.S. using the 1996 MEPS.(21) The MEPS is co-sponsored by the Agency for Health Care Policy and Research (AHCPR) and the National Center for Health Statistics. The sample of 9,400 households is a subsample of the households responding to the 1995 NHIS and is representative of the civilian noninstitutionalized population of the U.S. The survey was designed to yield comprehensive data that estimate the level and distribution of health care use and expenditures, monitor the dynamics of the health care delivery and insurance systems, and assess health care policy implications. MEPS is the third in a series of national probability surveys conducted by AHCPR on the financing and utilization of medical care in the United States. The National Medical Care Expenditure Survey (NMCES, also known as NMES-1) was conducted in 1977, and the National Medical Expenditure Survey (NMES-2) in 1987.
The MEPS collects data from a nationally representative sample of households through a rotating panel design. In this design, data are collected through a pre-contact interview followed by a series of five rounds of in-person interviews over a two year period of time. As a rotating panel survey, this series of data collection rounds is begun again each subsequent year on a new sample of households drawn from the NHIS sampling frame to provide overlapping panels of survey data, which when combined with other ongoing panels will provide continuous estimates of health care expenditures at both the person and household level.
Each MEPS interview collects information pertaining to a specific time period called the "reference period." The reference period for the first interview began January 1, 1996 and ended on the date of each responding unit's first round interview, conducted from March through June 1996. The health insurance section of the MEPS collects information about private and public health insurance programs. It identifies the household members covered by health insurance and various details about their plans. For employer sponsored coverage, a link is created to job characteristics collected in the employment section of the questionnaire. For individuals who are uninsured at the beginning of the year, information is collected on the length of time they have been uninsured. Additional questions clarify whether each person identified by each policy was covered throughout the reference period. Information for public insurance is collected on Medicare, Medicaid, Medicaid waiver programs, military sponsored plans, and other government programs. A questionnaire section on managed care determines whether household members that are either publicly or privately insured are covered under a managed care plan; additional questions ask about the characteristics of their managed care plans. The entire MEPS health insurance questionnaire is too large to include in this document. Instead, portions of the health insurance questions pertaining to Medicaid and the uninsured are presented in Appendix D.
Beauregard et al. used MEPS to develop a national estimate of the uninsured population based on sample persons who were uninsured continuously from January 1, 1996 to their first-round interview date 3 to 6 months later.(22) By this measure they found that 19 percent of nonelderly adults age 0 to 64 (44.5 million persons) and 15 percent of children age 0 to 17 (11 million children) were uninsured. Although these estimates appear higher than those of the CPS (9.8 million uninsured children) and other data sources, Beauregard et al. concluded that once time-period and definitional
issues are considered, their estimates are consistent with the findings of the CPS.(23) In reaching this conclusion, though, they assumed the CPS measured the uninsured throughout the previous year rather than at a point in time. If, instead, the CPS is viewed as a point-in-time estimate of the uninsured, then the MEPS and CPS findings are not consistent, since the MEPS estimate of those uninsured throughout a 3 to 6 month period should be considerably less than a point-in-time estimate. Additional research comparing MEPS and CPS estimates of the uninsured is warranted before firm conclusions can be drawn.