California Health Interview Survey (CHIS)

The California Health Interview Survey (CHIS) is the nation’s largest state health survey in the nation and a critical source of data on Californians, as well as on the state's various racial and ethnic groups. It is conducted by the UCLA Center for Health Policy Research in collaboration with the California Department of Public Health and the Department of Health Care Services. 

Each year, CHIS interviews more than 20,000 households on a wide range of health matters, from use of and access to health care, to health conditions and behaviors, to a range of topics that influence health: public program participation, housing, income and employment, climate change, food, gun violence, adverse childhood experiences, and much more.  

That information — whether focused on the smallest town in Northern California, a sprawling metropolitan area in South California, or statewide — can be translated into health stories that drive action: Who is most likely to go without medical care? Where are families going hungry? How has the COVID-19 pandemic impacted mental health? By collecting data on a wide range of health indicators, CHIS gives policymakers, advocates, health care providers, community organizations, researchers, journalists, and other stakeholders the evidence-based data to assess different aspects of health and then fight for policies that can improve the lives of Californians through better health and health care.

CHIS is a web and telephone survey conducted on a continuous basis, allowing the survey to generate timely one-year estimates. Participants in the survey are chosen at random and the sample is extensive enough to be statistically representative of California's diverse population.

CHIS covers a broad range of health topics, including: access to and use of health care, health insurance, health status, health conditions (asthma, diabetes, cancer, etc.), health behaviors (smoking, alcohol use, diet, etc.), public program participation (Medi-Cal, food stamps, CalWorks, etc.), mental health, oral health, immigrant health, intimate partner violence, food, childcare and school, employment, income, discrimination, and much more. Many core questions are repeated in each survey in order to measure significant shifts over time.  CHIS is conducted on a continuous basis, allowing the survey to generate timely one-year estimates. CHIS data are released annually in the following formats: Health Profiles in easy-to-read fact sheets containing key health statistics for the state; Publications through the UCLA Center for Health Policy Research; the Center’s Data Access Center with CHIS data that are not publicly available; AskCHIS, a free, online tool that enables the production of customized health statistics at multiple levels; AskCHIS Neighborhood Edition (NE), a free, online tool that enables the generation, mapping, and exporting of customized estimates at a local level; CHIS COVID-19 Estimates Dashboards, which provides early estimates focused on Californians’ health status, behaviors, and experiences related to the COVID-19 pandemic; and Public Use Files (PUFs) which contain a full (one-year) cycle of CHIS data in a variety of data formats, including SAS, SPSS, and STATA.

CHIS provides representative data on all 58 counties in California and provides a detailed picture of the health and health care needs of California’s large and diverse population. Participants in the CHIS survey are chosen at random and the sample is extensive enough to be statistically representative of California's diverse population. In 2022, 22,423 households in Los Angeles County were surveyed, including 21,463 adults, 985 adolescents, and 3,395 children. Although the sample sizes are not enormous for each disparity population, analysis of CHIS data can provide a window for health metrics for prevalent conditions and for the larger special populations.

For more information, please visit the CHIS website.

Last updated
November 20, 2023