Asthma is consistently one of the most searched data variables in AskCHIS and AskCHIS Neighborhood Edition.

About 1 in 4 Californians, or 5.7 million people, had ever been diagnosed with asthma in 2021, and nearly a million of them are children 17 or younger. Researchers dissect California Health Interview Survey’s estimates to analyze asthma prevalence among different socioeconomic groups, including by age, race and ethnicity, citizenship status, income level, and more. They find out who is vulnerable to the disease and recommend who can take what steps to help them navigate it.

Research on Asthma

Researchers at UCLA CHPR examined the relationship between social position (e.g., poverty level, age, gender, race, ethnicity), environmental context (e.g., traffic/air pollutants near homes, access to care), and health behaviors (e.g., smoking, overweight/obesity) with various asthma health outcomes. Examples of recent research using UCLA CHPR data include a look at which California children had the highest prevalence of asthma (Black or African American children; men; children ages 6–11; children whose parent spoke English very well) and how — or whether — they managed symptoms; students missing school due to asthma; and the variation in asthma rates among subgroups of Asian children (8.7% of Korean children, compared with 16.1% of Filipino children).

Research on adults included an analysis of the likelihood of a nonsmoker having an asthma attack after exposure to secondhand smoke compared with someone not exposed (109% higher odds among men); whether a patient’s food insecurity was tied to a delay them refilling their asthma medicine prescription; and the effect policy changes that lowered truck traffic pollution in port-adjacent neighborhoods had on Medi-Cal patients’ emergency room use for asthma and chronic pulmonary disease visits.

Data on Asthma

The California Health Interview Survey (CHIS), the largest state health survey in the nation, has several easy-to-use online health query tools, where you can search for data on asthma at the state and local levels.

Data include: adults, teen, and children who have ever been diagnosed with asthma; asthma episode/attacks in past 12 months; school days missed due to asthma; daily medication to control asthma; and more, and can be examined across location and a range of sociodemographic factors, including race and ethnicity, age, gender, income and poverty level, and much more.

Asthma at a Glance


of children ages 0–17 in California have ever been diagnosed with asthma (Source: 2021 CHIS)


of California adults have ever been diagnosed with asthma  (Source: 2021 CHIS)


of Californians took daily medication to control asthma in 2021 (Source: 2021 CHIS)

Asthma Data in Dashboards

CHIS asthma data are used by local, state, and federal government agencies and organizations to populate numerous health indicator dashboards, including: Dashboard

asthma rates by California county Dashboard

current and lifetime asthma prevalence by California county

California Department of Public Health California Asthma Dashboard

state- and county-level asthma data

Be Healthy Sacramento Community Dashboard

health/respiratory diseases including rates of asthma