The impact of survey design modifications on health insurance coverage estimates in a National Longitudinal Health Care Survey

摘要

National health insurance coverage estimates for the overall population and specific population subgroups are critical to policymakers and others concerned with access to medical care and the cost and sources of payment for that care. The Medical Expenditure Panel Survey (MEPS) is one of the core health care surveys in the United States that serves as a primary source for these essential national health insurance coverage estimates. The survey is designed to provide annual national estimates of the health care use, medical expenditures, sources of payment and insurance coverage for the U.S. civilian non-institutionalized population. In 2007, the survey experienced two dominant survey design modifications: (1) a new sample design attributable to the sample redesign of the National Health Interview Survey, and (2) an upgrade to the CAPI platform for the survey instrument, moving from a DOS to a Windows based environment. This study examines the impact of these survey design modifications on the national estimates of insurance coverage. The overlapping panel design of the MEPS survey and its longitudinal features are particularly well suited to assess the impact of survey redesign modifications on estimates. Since two independent nationally representative samples are pooled to produce calendar year estimates, one has the capacity to compare estimates based on the "original survey design" in contrast to those derived from the "survey redesign." This paper examines the correlates of nonresponse incorporated in the estimation techniques and adjustment methods employed in the survey, and the measures utilized for post-stratification overall and by panel. Particular attention is given to assessing the level of convergence in coverage estimates based on the alternative designs as well as the alignment of model based analyses that discern which factors are associated with health insurance classifications. The paper concludes with a discussion of strategies under consideration that may yield additional improvements in the accuracy for these critical policy relevant survey estimates.