NHIS Sources

Variable	Year	Supplement
INTV_QRT	2023	Household (core questionnaire)
INTV_QRT	2022	Household (core questionnaire)
INTV_QRT	2021	Household (core questionnaire)
INTV_QRT	2020	Household (core questionnaire)
INTV_QRT	2019	Household (core questionnaire)