Frequently Asked Questions

1. Why does the NHIS include questions about physical activity on its surveys?

Physical activity is associated with improved health and reduced mortality. The NHIS is charged with monitoring progress in increasing prevalence of this important health behavior among U.S. adults.

2. When did the NHIS first ask questions on adult physical activity?

The first questions on adult physical activity appeared on the NHIS in 1975.

3. Have physical activity questions remained the same since 1975?

No. There have been substantial changes in the conceptualization and measurement of physical activity over the years, paralleling changes in physical activity research.

4. Is the NHIS the only national survey that collects data on adult physical activity?

No. Questions about adult physical activity are asked in other U.S. surveys, including the National Health and Nutrition Examination Survey (NHANES) and the Behavioral Risk Factor Surveillance System (BRFSS). For an overview of national physical activity surveillance systems, please visit this website.

5. Will there be more changes to the physical activity questions?

The National Health interview Survey questionnaires will undergo a major redesign in 2018 and changes to the adult physical activity questions are expected. For current information about the redesign, visit the NHIS 2018 Redesign home page.

6. Did the NHIS adult physical activity questions change when the 2008 Physical Activity Guidelines were issued?

No. The existing NHIS physical activity questions, which have been in the annual core questionnaire since 1997, provide the data needed for monitoring adult physical activity prevalence specified in the 2008 Guidelines. The questions have been nearly the same since 1997 and identical since 2004.

7. I’m having trouble downloading data files for 2005 and earlier. Is there something wrong with the data?

No. The problem likely is due to using a 64-bit Microsoft operating system. NHIS Public Use data sets from 1970-2005 with the .exe file type are unable to be extracted on 64-bit computers running Microsoft operating systems. Data users are advised to rename the .exe files as .zip files and the data sets will extract correctly. This workaround is suggested for data years 1970-2005. For years 2006-2009, the .exe files do extract correctly. Beginning in 2010, NHIS data files are released as .zip files.

8. How can I get more information about NHIS physical activity data?

For further information, you may contact:
nhislist@cdc.gov

Division of Health Interview Statistics
(301) 458-4901 or toll free 1-800-232-4636