Effect of Smoking on the Association Between Environmental Triggers and Asthma Severity Among Adults in New England

Abstract

To identify environmental triggers associated with asthma severity and the potential modifying effect of cigarette smoke, the authors examined the relationship between sociodemographic characteristics, controller medication use, environmental triggers, and actions taken to reduce triggers on asthma severity among adults (≥18 years) residing in New England using the Behavior Risk Factor Surveillance Survey (BRFSS) Asthma Call-Back data. Asthma severity was categorized as intermittent, mild persistent, moderate persistent, and severe persistent according to the National Asthma Education and Prevention Program guidelines. In weighted logistic regression models, asthma severity was analyzed for 3075 adults with active asthma in Connecticut, Massachusetts, Maine, New Hampshire, and Vermont from 2006 to 2007. The odds of more severe asthma were 1.8 for smokers as compared with nonsmokers (95% confidence interval [CI] = 1.1, 3.1). Among current smokers, the odds of more severe asthma among those who were exposed to wood stoves was 2.4 (95% CI = 1.1, 5.7) as compared with those who were not exposed to wood stoves. Among nonsmokers, those who had a high school education or less (odds ratio [OR] = 2.0, 95% CI = 1.2, 3.3), had some college or technical school education (OR = 2.1, 95% CI = 1.2, 3.7), or had any comorbidity factors such as chronic obstructive pulmonary disease, emphysema, or bronchitis (OR = 2.5, 95% CI = 1.6, 3.8) were significantly associated with more severe asthma. Furthermore, the odds for more severe asthma were 2.1 (95% CI = 1.1, 4.0) among nonsmokers who were exposed to environmental tobacco smoke (ETS) as compared with those who were not exposed to ETS. The effect of environmental triggers on asthma severity differs among smokers and nonsmokers, even after controlling for sociodemographic factors, medication use, and actions taken to reduce triggers. Targeting smokers with asthma and making modifications to the environment may be important for reducing asthma severity among a high-risk population.