By Julia A. Rivera Drew, Kari C.W. Williams, and Natalie Del Ponte
The IPUMS NHIS project offers integrated versions of the National Health Interview Survey (NHIS) data, the leading source of nationally representative information on the health of the U.S. population. The National Center for Health Statistics (NCHS) collects the NHIS data through face-to-face interviews covering information about health, health insurance coverage, health care utilization, socioeconomic characteristics, and demographics of all household members. It is representative of the civilian, non-institutionalized U.S. population with annual samples ranging between 30,000-50,000 households and 75,000-100,000 people. NCHS has collected the NHIS annually since 1957 (with digital copies of the data available going back to 1963), making it the longest running annual survey of health in the world.
Periodically, aspects of data collection – such as the sampling frame, oversampled populations, or questionnaire content – change to better capture changes in the most pressing health concerns of Americans or changes in the demographic makeup of Americans and where they reside within the U.S. Most of these changes are modest, reflecting changes in U.S. population composition and distribution detected in the most recent decennial census. However, 2019 heralded the largest change in NHIS data collection since 1997. In fall 2020, the NCHS will release the 2019 public use data files, the first data collected under the newly redesigned NHIS. The upcoming release of the 2019 data warrants a look back at how NCHS collected the NHIS data over the 1997-2018 period.