Using enrollment records to evaluate self-reports of monthly coverage in the redesigned current population survey health insurance module.

OBJECTIVE: To evaluate the veracity of self-reports of month-level health insurance coverage in the Current Population Survey Annual Social and Economic Supplement (CPS).

DATA SOURCES AND STUDY SETTING: The CHIME (Comparing Health Insurance Measurement Error) study used health insurance enrollment records from a large regional Midwest insurer as sample for primary data collection in spring 2015.

STUDY DESIGN: A sample of individuals enrolled in a range of public and private coverage types (including Medicaid and marketplace) was administered the CPS health insurance module, which included questions about month-level coverage, by type, over a 17-18-month time span. Survey data was then matched to enrollment records covering that same time frame, and concordance between the records and self-reports was assessed.

DATA COLLECTION/EXTRACTION METHODS: Sample was drawn by the insurer's informatics specialists and Census Bureau interviewers conducted the survey. Following data collection, updated enrollment records were matched to the survey data to produce a person-level file of coverage by type at the month-level.

PRINCIPAL FINDINGS: For 91% of the overall sample, coverage status and type were reported accurately for at least 75% of observed months. Results varied somewhat by stability of coverage. Among those who were continuously covered throughout the 17-18 month observation period (which comprised 64% of the overall sample), that level of reporting accuracy was observed for 94% of the sample; for those who had censored spells (34% of the overall sample), the figure was 87%; and among those with gaps and/or changes according to the records (2% of the overall sample), for 82% of the group at least 75% of months were reported accurately.

CONCLUSIONS: Findings suggest that reporting accuracy of month-level coverage in the CPS is high and that the survey could become a valuable new data source for studying the dynamics of coverage, including the Medicaid unwinding.