The National Health and Nutrition Examination Survey (NHANES) is a nationally representative, ongoing research survey designed to measure the health and nutritional status of adults and children in the United States. NHANES uses a combination of interviews, physical examinations, and laboratory tests to collect data. The NHANES program suspended field operations in March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. As a result, data collection for the NHANES 2019-2020 cycle was not completed and the collected data are not nationally representative. Therefore, data collected from 2019 to March 2020 were combined with data from the NHANES 2017-2018 cycle to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data.
National Center for Health Statistics, Centers for Disease Control and Prevention. United States National Health and Nutrition Examination Survey Pre-Pandemic 2017-2020. Hyattsville, United States of America: National Center for Health Statistics, Centers for Disease Control and Prevention, 2022.
