Integrated Health Interview Series

The Integrated Health Interview Series (IHIS) is a harmonized set of data for over 50 years (1963-present) of the National Health Interview Survey (NHIS). The NHIS is the principal source of information on the health of the U.S. population, covering such topics as general health status, the distribution of acute and chronic illness, functional limitations, access to and use of medical services, insurance coverage, and health behaviors (such as exercise, diet, and tobacco and alcohol consumption). On average, the survey covers 100,000 persons in 45,000 households each year. IHIS facilitates cross-time comparisons of these invaluable survey data by coding variables identically across time and providing detailed documentation covering comparability issues for harmonized variables. IHIS data are distributed for free through an online data access system (ihis.ipums.org) to any person who agrees to follow the responsible use guidelines set by the National Center for Health Statistics.