Since its inception in 2001, the California Health Interview Survey (CHIS) has been an invaluable resource for credible and comprehensive data on the health and health care needs of Californians.
As the largest state health survey in the nation, CHIS understands the importance of data and the responsibility of ensuring the highest quality survey design and methodology to obtain a representative sample of the state's population.
CHIS conducts rigorous reviews of the survey design, data collection methods, data processing procedures, weighting and variance estimation, and other designs and methods, and has continued to evolve and strengthen the survey.
Learn more about our design and methodology:
Design
Starting in 2019, CHIS transformed from a dual-frame landline/cell phone random-digit dial methodology to a mixed-mode (web and telephone) survey that uses an address-based sampling methodology. Learn about the CHIS sample and view sample sizes by county, race, and ethnicity.
Questionnaires and Topics
Each year, CHIS surveys adults, adolescents, and children on a broad range of health topics. View a full list of survey topics and download questionnaires from the last 20 years.
Methodology Reports
From oversamples to targeting through predictive modeling to data collection methodology innovations, learn how CHIS is continuing to evolve its methodology to remain relevant. Read methodology reports, briefs, and papers released over the last 20 years.
CHIS is publicly recognized as a Charter Member of the American Association of Public Opinion Research (AAPOR) Transparency Initiative. The certification signifies a commitment to transparent survey research practice and effective disclosure of research methods.
CHIS data adds credibility to all the work that we do.
Pamela Lane, Vice President, Health Informatics at California Hospital Association
CHIS at a Glance
22,480
CHIS interviewed 22,480 households in 2023, including 21,671 adults, 968 adolescents, and 3,377 children.
89%
of 2023 CHIS interviews were completed on the web, and 11% were completed by telephone
6
languages — the 2023 CHIS was conducted in English, Spanish, Chinese (Mandarin and Cantonese), Vietnamese, Korean, and Tagalog