Asthma incidence among children and adults in participating states: Findings from the Behavioral Risk Factor Surveillance System Asthma Call-back Survey- United States, 2006-2008

Background: Asthma, a chronic respiratory condition affecting 8.2% of the U.S. population (2009), causes significant societal and economic burden, resulting in missed school/work days, activity limitations, and increased healthcare utilization. Annual estimates of asthma prevalence are available from national surveys, but these surveys do not routinely collect asthma incidence data. The Asthma Call-back Survey (ACBS), implemented in 2006, provides detailed asthma data that supplements Behavioral Risk Factor Surveillance System (BRFSS) Core data. We analyzed BRFSS Core and ACBS data to estimate annual asthma incidence and determine if these rates differed by age group, sex, and race/ethnicity.

Methods: BRFSS and ACBS data from 2006–2008 participating states (24 states and DC in 2006; 34 states and DC in 2007, 2008) were analyzed to calculate annual incidence. Incident cases of asthma were defined as answering, “yes,” to the BRFSS Core “lifetime asthma” question and responding, “Within the past 12 months,” to the ACBS question about time of asthma diagnosis.

Results: Estimated asthma incidence among adults was 4.0/1000 (2006), 3.9/1000 (2007), and 3.6/1000 (2008). Estimated asthma incidence among children was 13.6/1000 (2006), 9.9/1000 (2007), and 14.0/1000 (2008). Asthma incidence was higher in children compared to adults (2006–2008) (p<.05).

Conclusions: We successfully estimated asthma incidence for adults and for children, and rates were consistently higher in children than adults. However, we were unable to demonstrate statistically significant differences in asthma incidence by sex or race/ethnicity in all three years. Our estimates will help asthma control programs target asthma-related resources to populations most affected.