Accuracy of Self-reported Health Insurance Coverage among Medicaid Enrollees
The largest portion of the Medicaid undercount is caused by survey reporting error; that is, Medicaid recipients misreport their enrollment in health insurance coverage surveys. In this study, we sampled known Medicaid enrollees to learn how they respond to health insurance questions and to document correlates of accurate and inaccurate reports. We found that Medicaid enrollees are fairly accurate reporters of insurance status and type of coverage, but some do report being uninsured. Multivariate analyses point to the prominent role of program-related factors in the accuracy of reports. Our findings suggest that the Medicaid undercount should not undermine confidence in survey-based estimates of uninsurance.
Call, K.T., G. Davidson, M. Davern, E.R. Brown, J.E. Kincheloe, J.G. Nelson. 2008. "Accuracy of self-reported health insurance coverage among Medicaid enrollees." Inquiry 45(4): 438-56.
Economic Impact on Minnesota’s Health Care Delivery System
Presentation by Lynn Blewett to the Minnesota State Legislature at a joint meeting of the health care and human services finance and policy committees in Saint Paul, MN, February 10 2009.
The Medicaid Undercount and the Policy Relevance of Measurement Error in the Current Population Survey
Michael Davern's presentation titled, "The Medicaid Undercount and the Policy Relevance of Measurement Error in the Current Population Survey." Washington Statistical Society Seminar, Nov 13, 2008 in Washington DC.
Uncovering the Missing Medicaid Cases and Assessing Their Bias for Estimates of the Uninsured
Call, K. T., G. Davidson, A. S. Sommers, R. Feldman, P. Farseth, and T. Rockwood. 2001. “Uncovering the Missing Medicaid Cases and Assessing Their Bias for Estimates of the Uninsured.” Inquiry 38 (4): 396-408.
General population surveys of health insurance coverage are thought to undercount Medicaid enrollment, which may bias estimates of the uninsured. This article describes the results of an experiment undertaken in conjunction with a general population survey in Minnesota. Responses to health insurance questions by a known sample of public program enrollees are analyzed to determine possible reasons for the undercount and the amount of bias introduced in estimates of uninsured people. While public program enrollees often misreport the type of coverage they have, the impact on estimates of those without insurance is negligible. Restrictions to generalizing the finding beyond this study are discussed.