Drug

Refers to prescription drug or pharmaceutical agents, prescribed by a physician or other authorized medical professional, for the prevention or treatment of medical conditions or disease.

National Health and Nutrition Examination Survey (NHANES)

Prescription drug information from NHANES III and from NHANES 1999–2000 and later cycles (referred to as continuous NHANES) was collected during in-person interviews conducted in participants’ homes. Starting with NHANES 2001–2002 data, participants were asked whether they had taken any medication in the past 30 days for which a prescription was needed, excluding prescription dietary supplements. For NHANES III and NHANES 1999–2000, the question wording differed slightly: participants were asked whether they had taken a prescription medication in the past month. For participants younger than age 16, a parent or proxy respondent provided the information. Across all survey years, participants who answered yes were asked to provide the prescription medication containers for the interviewer. For each medication reported, the interviewer entered the product’s complete name from the container. If no container was available, the interviewer asked the participant to verbally report the name of the medication. In addition, participants were asked how long they had been taking the medication and the main reason for use. The respondents who reported taking prescription medicines in the past month but did not answer some or all of the remaining questions about the prescription medicines, such as the name of the medication or the duration they took the medicine, are coded as either “blank but applicable” or “don’t know” and were excluded from the analysis.

Drug data from NHANES provide a snapshot of all prescribed drugs reported by a sample of the U.S. civilian noninstitutionalized population for a 30-day period (or past month, for earlier survey years). In addition to capturing information on drugs taken daily, drugs taken on an irregular basis, such as every other day, once per week, or for a 10-day period, were captured in the 30-day recall period.

Although NHANES field operations and weighting procedures were modified because of the COVID-19 pandemic for the 2017–March 2020 prepandemic and August 2021–August 2023 survey periods, the prescription drug questionnaire and core data collection procedures remained substantially unchanged.

For more information on prescription drug data collection and coding in NHANES, see: National Health and Nutrition Examination Survey Questionnaires, Datasets, and Related Documentation. Also see Sources and Definitions, National Health and Nutrition Examination Survey (NHANES).