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NHIS: Early Release Estimates Show Unchanged Coverage Rates during First Half of 2020, although NCHS Reports Evidence of Nonresponse Bias due to COVID-19February 15, 2021:
The National Center for Health Statistics (NCHS) has just published health insurance coverage estimates for the first half of 2020 (January to June) from the National Health Interview Survey (NHIS) as part of the NHIS Early Release Program. These estimates are some of the first available coverage estimates for 2020 from a federal survey and among the first estimates to cover the beginning of the coronavirus (COVID-19) pandemic in the United States.
Topline Estimates from January-June 2020
At a high level, the new estimates show no significant changes in coverage type or uninsured rate when compared to the same period of time in 2019. Among nonelderly adults (ages 18 to 64) surveyed between January and June 2020, 13.4% were uninsured at the time of interview, 20.8% had public coverage, and 67.9% had private coverage. These rates were 14.7%, 20.4%, and 66.8%, respectively, from January to June 2019.
Nonresponse Bias Report for April-June, 2020 (Q2)
NCHS released a report to accompany the January-June 2020 estimates that presents a preliminary analysis of a drop in response rates in Q2 2020 (April-June).
NHIS data collection, which is typically conducted by making personal visits to respondents’ homes, was significantly impacted by the COVID-19 pandemic beginning in Q2 2020: Personal visits were suspended beginning on March 19, 2020, and data was collected by telephone instead. As a result of the shift to telephone-only interviewing, the sample household response rate declined from 60.0% in Q1 (January-March) to 42.7% in Q2; the adult response rate fell from 57.9% to 41.1%; and the child response rate dropped from 57.6% to 40.1%.
NCHS researchers compared the characteristics of Q2 respondents to the characteristics of respondents from Q1 to determine whether the smaller Q2 sample was systematically biased in any way and found that lower-income and renter households were underrepresented in the Q2 sample. This points to potential nonresponse bias and to the possibility that the actual uninsured rates for Q2 2020 were higher than the NHIS early release estimates indicate, as lower-income and renter households tend to have higher rates of uninsurance than do middle- and higher-income households and home-owning households.
SHADAC will continue to monitor all subsequent early data releases for 2020 from the NHIS survey, and will provide updates on any new methodology reports such as the investigation into nonresponse bias for Q2 2020 provided by NCHS.
Notes about the Estimates
The above estimates provide a point-in-time measure of health insurance coverage, indicating the percent of persons with that type of coverage at the time of the interview.
All changes described compare January-June 2020 to January-June 2019, and are statistically significant at the 95% confidence level unless otherwise specified.
Cohen, R.A., Terlizzi, E.P., Cha, A.E., & Martinez, M.E. (2021). Health insurance coverage: Early release of estimates from the National Health Interview Survey, January–June 2020. National Center for Health Statistics (NCHS). https://www.cdc.gov/nchs/data/nhis/earlyrelease/insur202102-508.pdf
Dahlhamer, J.M., Bramlett, M.D., Maitland, A., & Blumberg, S.J. Preliminary evaluation of nonresponse bias due to the COVID-19 pandemic on National Health Interview Survey estimates, April-June 2020. National Center for Health Statistics (NCHS). https://www.cdc.gov/nchs/data/nhis/earlyrelease/nonresponse202102-508.pdf?ACSTrackingID=USCDC_374-DM49266&ACSTrackingLabel=NHIS%20Early%20Release%3A%20Non-response%20Bias&deliveryName=USCDC_374-DM49266