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The National Health Interview Survey Early Release Program

The Early Release (ER) Program of the National Health Interview Survey (NHIS) provides analytic reports and preliminary microdata files on an expedited schedule. NHIS data users can have access to these very timely reports and microdata files without having to wait for the final annual NHIS microdata files to be released in late June following the end of each data collection year. ER reports and microdata files are produced prior to final data editing and final weighting to provide early access to the most recent information from NHIS. Some ER products are available as soon as nine months before the public use files are released. Below are descriptions of and links to each type of ER product.

The online report Selected Estimates Based on Data from the National Health Interview Survey is published quarterly and provides estimates of 15 selected key health indicators (one of which is health insurance). The first report for each data collection year (January through December) is released in about September and is based on NHIS data from the previous January through March. Each of the three subsequent quarterly reports is based, respectively, on an additional three months of data.
The online report Health Insurance Coverage: Estimates from the National Health Interview Survey is published quarterly and provides additional detailed estimates of health insurance coverage by selected demographic characteristics. The first report for each data collection year (January through December) is released in about September and is based on NHIS data from the previous January through March. Each of the three subsequent quarterly reports is based, respectively, on an additional three months of data.
The online report Wireless Substitution: Estimates from the National Health Interview Survey is published in about May and December of each year and provides updated estimates of trends in use of landline and wireless telephones by persons and in households.
Other online ER reports and tabulations on special topics are released on an as-needed basis. Some of these also are found at Responses to Recent Health Policy Data Requests.
Preliminary Quarterly Microdata Files[PDF - 153 KB] containing selected NHIS variables are made available via the NCHS Research Data Center (RDC). For each data collection year, these files are made available four times: in about September (with data from the first quarter), in about November (with data from the first two quarters), in about February of the next year (with data from the first three quarters) and in about May of the next year (with data from all four quarters). Analysts wishing to use the files should follow standard procedures for using the RDC. Note that NCHS has RDC locations in Hyattsville, Maryland and Atlanta, Georgia, and NCHS data can also be accessed at Census Bureau RDCs and through remote access. See NCHS Research Data Center.

A new sample design was implemented starting with the 2016 NHIS. Some of the differences between estimates for 2016 and estimates for earlier years may be attributable to the new sample design. In addition, if data from any year before 2016 are combined with data from 2016 and beyond, variance estimation becomes more complex, as the years being pooled fall into different sample design periods. Different sample design periods should be treated as statistically independent. For further information on variance estimation for data pooled across sample design periods, please see the 2015 Survey Description Document[PDF - 1.2 MB].