BRFSS Data-Asthma Prevalence Description

This dataset contains the estimated percent of California adults (18 and older) with lifetime and current asthma (asthma prevalence), by year. The data are derived from the California Behavioral Risk Factor Surveillance System (BRFSS). These data are based on self-report from telephone surveys and are subject to bias and low response rates. In 2012, the survey methodology of the BRFS changed significantly so that the survey would be more representative of the general population. Several changes were implemented: 1) the survey included both cell and landline random-digit dial components, 2) residents of college housing were eligible to complete the survey, and 3) new methods were used to calculate the survey weights. Due to these changes, estimates from 1984 – 2011 are not comparable to estimates from 2012 and beyond. CDPH and CDC recommend not conducting analyses where estimates from 1984 – 2011 are compared with analyses using the new methodology, beginning in 2012. This includes analyses examining trends and changes over time. Please refer to the attachment for AsthmaPrevalence-Adults-by-Year-CA-Description.pdf.