Health Insurance: Federal Data Sources for Analyses of the Uninsured

Publication Date: February 2002

Publisher: Library of Congress. Congressional Research Service

Author(s):

Research Area: Health

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Abstract:

The number of people without health insurance continues to be a key public policy concern. Numerous sources of data, both public and private, gather information on the uninsured but they produce estimates that vary widely. This report discusses estimates of the number of uninsured using data from four federally administered surveys: the March Supplement to the Current Population Survey (CPS), the Survey of Income and Program Participation (SIPP), the National Health Interview Survey (NHIS), and the Medical Expenditure Panel Survey (MEPS).

In 1998 (the most recent year for which data are available from all four surveys), estimates of the number of uninsured for the full year ranged from 21.2 million using SIPP data to 43.6 million using data from the March CPS, a difference of more than 22 million individuals. Estimates of the number of uninsured at a point in time as well as the number who were ever uninsured during the year also vary among MEPS, NHIS, and SIPP (the March CPS does not support these estimates). The number of uninsured at a point in time in 1998 ranged from 39.2 million from SIPP to 42.3 million from MEPS. Estimates of the number who were ever uninsured during 1998 ranged from 50.0 million from NHIS to 60.3 million from MEPS.

To date, no clear consensus has emerged that explains why these differences exist in the survey estimates of the uninsured. However, researchers have offered a number of explanations that may account for some of the variation.