National Health Interview Survey Early Release Program
The Early Release (ER) Program of the National Health Interview Survey (NHIS) provides estimates, analytic reports, and preliminary microdata files on an expedited schedule. NHIS data users can have access to these very timely estimates, reports, and microdata files without having to wait for the release of the final annual NHIS microdata files by selected demographic characteristics.
- Preliminary Evaluation of Nonresponse Bias Due to the COVID-19 Pandemic on NHIS Estimates, April-June 2020 [PDF – 274 KB] (February 2021)
- Preliminary Evaluation of the Impact of the 2019 NHIS Questionnaire Redesign and Weighting Adjustments on Early Release Program Estimates [PDF – 586 KB] (September 2020)
Preliminary microdata files
Selected NHIS variables are made available via the NCHS Research Data Center (RDC) with each ER product release. NCHS has RDCs located in Hyattsville, Maryland and Atlanta, Georgia. NCHS data can also be accessed at Federal Statistical RDCs managed by the U.S. Census Bureau and through remote access. Analysts wishing to use the files should follow standard procedures for using the RDC.
In January 2019, NHIS launched a redesigned questionnaire. Following this redesign, some ER indicators have changed, thus, the contents of preliminary microdata files are different from previous versions. Two files are available for each the Sample Child Core and Sample Adult Core: one with information on wireless substitution and another with information on key health indicators and health insurance measures. Where data are available for both adults and children, data users should concatenate the adult file and child file together in order to calculate estimates for all ages. Visit the NHIS website for more information on the design, content, and use of NHIS.
The ER program released a series of reports and tabulations on health care access and utilization topics on an as needed basis. Some of these reports or tabulations are also available at Responses to Recent Health Policy Data Requests.