Codes and Frequencies
Description
For all persons, INTERVWMO indicates the month that the National Health Interview Survey (NHIS) was conducted.
Comparability
This variable is fully comparable across all years with two exceptions. First, it was not provided in the original data in 2019. Second, for the last calendar quarter of the year, only an aggregated value, 96 "November-December" was made available. Data was not collected in October 2025 due to a prolonged government shutdown that disrupted data collection operations.
Universe
- 1969-2018: All persons.
- 2020-2025: All persons.
Availability
- 1969-2018, 2020-2025
Weights
- 1969-2003 : HHWEIGHT
- 2004-2018 : PERWEIGHT
- 2020-2024 : SAMPWEIGHT