Association for Public Policy Analysis & Management

Research Objective: First, to compare estimates of health insurance status (covered/not covered) and coverage type (e.g., non-group coverage, Medicaid) as reported in the Current Population Survey (CPS) to known coverage status and type as indicated in health plan enrollment records. Second, we explore the offsetting influence of misreporting coverage across individuals with different insurance types in the CPS. Finally, we project the impact of coverage type misreporting for estimates of the prevalence of insurance coverage derived from state-specific and national benchmark data.

Study Design: Using administrative records from a private health plan, individuals known to be enrolled in a range of different coverage types (public and private, including the marketplace) were randomly selected and assigned to a test survey mimicking the CPS recently redesigned Annual Social and Economic Supplement (ASEC).

Population Studied:Non-elderly adults enrolled in a Minnesota health plan were surveyed by telephone in May and June of 2015. Sample were randomly selected from five coverage type strata: employer-sponsored insurance (ESI), non-group coverage, qualified health plan from the Marketplace, Medicaid and MinnesotaCare (basic health plan). The analysis dataset includes data on non-elderly 1,989 people from 1,196 households assigned to the CPS ASEC survey treatment.

Preliminary Findings: Among individuals indicated by enrollment records to be covered by one of the five coverage types, overall 98 percent reported some type of comprehensive coverage. There was some variation by strata; 96 percent of public enrollees reported being covered compared to 98-99 percent for all other plan types. Reporting accuracy of particular coverage type varied by strata, with 94 percent of individuals with ESI reporting this type. For all other strata, correctly defining coverage type (and hence reporting accuracy) hinged on not one but several self-reported data points on coverage: general source of coverage (government versus direct-purchase), whether the coverage was from the marketplace, whether there was a premium and, if so, whether the premium was subsidized. Preliminary results show that reporting accuracy for public coverage was about 80 percent and for non-group (including from the marketplace) reporting accuracy was about 77 percent.

We also explore the offsetting influence of misreporting coverage across individuals with different insurance types in the CPS. We then project the impact of these offsetting influences of survey misreporting on benchmark survey estimates of the prevalence of insurance type. To facilitate generalizability, we contrast CHIME CPS result with and without the MinnesotaCare strata given that only small group of states have public programs that charge a premium and bear a unique name.

Conclusion: CHIME results corroborate past findings that self-reported coverage status (insured/uninsured) in the CPS survey is quite accurate. There is no evidence of a drop-off in self-reported accuracy of coverage status (insured/uninsured). Accuracy of self-reported coverage type is generally problematic and appears to be more complicated following the introduction of new health insurance products and new pathways to enrolling in coverage. Understanding overall bias in survey estimates of coverage type requires information about misreporting of both private and public insurance.