Department SummaryThe California Health Interview Survey (CHIS) is the largest population-based state health survey in the nation and the premier source of credible and comprehensive data on the health and health care needs of California?s large and diverse population. A model for health surveys for other states, CHIS is committed to ensuring everyone has access to data - policymakers, advocates, health care providers, community organizations, researchers, journalists, and the public - to fight for policies that will improve the lives of Californians through better health and health care. We make sure that data didn?t just sit on a shelf but was accessible and widely disseminated through our public use files and AskCHIS free web query tool.