Risk Factors for Asthma Incidence Among Adults: United States, 2006–2008 Behavioral Risk Factor Surveillance System (BRFSS) and Asthma Call-back Survey (ACBS)

Background: A better understanding of asthma incidence and its risk factors is important for developing interventions for disease prevention. Previously we have reported that estimated asthma incidence rates differed by age group, sex, and race/ethnicity. The purpose of this analysis is to determine if asthma incidence rates among adults differ by additional demographic and social factors.

Method: BRFSS and ACBS data from the 37 participating states during 2006–2008 were analyzed to calculate 12-month asthma incidence rates. Logistic regression analyses were used to assess the independent contribution of each risk factor to recent asthma onset.

Results: Estimated adult asthma incidence rate (IR) was 3.8/1000. Among the assessed risk factors, sex, body mass index (BMI), income level, and smoking status were significantly associated with asthma incidence. Women [Odds/Ratio (OR): 2.03, 95% CI: 1.50-2.73; IR: 4.87/1,000 vs. 2.77/1,000]; obese adults [ OR:1.75, 95% CI: 1.26-2.43; IR: 4.96/1,000 vs. 3.64/1,000]; adults with <=$15,000 household income [OR: 1.77, 95% CI: 1.16-2.69; IR: 6.57/1,000 vs. 3.51/1,000]; current smokers [OR: 1.61, 95% CI: 1.13-2.30, IR: 4.13/1,000 vs. 3.34/1,000 ]; and former smokers [OR: 1.87, 95% CI: 1.31-2.68] were more likely than their corresponding reference groups (i.e., men, adults with normal and underweight, adults with >$15,000 income, and never-smokers, respectively) to be diagnosed with asthma in the past 12 months.

Conclusions: We identified several socio-demographic risk factors: sex, BMI, income level and cigarette smoking that were associated with asthma incidence. These findings distinguish additional asthma onset risk factors among U.S adults and may help asthma control programs provide targeted interventions to reduce disease.