372 Multicenter Study of Cigarette Smoking Among Adults With Asthma Exacerbations in the Emergency Department, 2011-2012

Abstract

Cigarette smoke is a recognized respiratory irritant and habitual smoking can lead to a decline in pulmonary function and chronic lung disease. Current and former smokers are more likely to need emergency care for a variety of illnesses, including asthma; approximately 10% of emergency department (ED) visits for asthma exacerbations have been attributed to smoking. Previous studies dating as far back as the late 1990’s demonstrated a high prevalence of cigarette smoking in patients presenting to the ED with asthma exacerbations, with smoking rates between 33 and 35%. Despite the clinical and public health importance, there have been no recent multicenter efforts to characterize smoking status in this high-risk patient population. We aimed to update the prevalence of cigarette smoking among ED patients with asthma exacerbations and to identify factors associated with smoking. The 36th Multicenter Airway Research Collaboration (MARC-36) study was a multicenter chart review study of 48 EDs across 23 US states that participated in earlier studies during 1996 and 2001. Briefly, we identified all ED patients aged 18 to 54 years with asthma exacerbations during 2011-2012, and then randomly sampled 40 patients per site. We classified patients into three groups based on smoking status: never smoker, former smoker, and current smoker. Smoking status was available for 1801 (90%) of 2,000 patients, and these patients comprised the analytic sample. We fit multivariable logistic regression models to examine independent predictors of being a current smoker. Of 1,801 ED patients, never smokers accounted for 51% (95% CI, 49%-54%), former smokers 13% (95% CI, 11%-14%), and current smokers 36% (95%CI, 34%-38%). The multivariable model demonstrated several independent predictors for current smoking: older age (age 30-39 and 40-54 years versus age 18-30 years), non-Hispanic white or black (versus Hispanic), having public or no insurance (versus private insurance), and not having an asthma specialist (all P < .05). This large multicenter study of ED patients with asthma exacerbations demonstrated that one in three patients were current smokers. The observed prevalence of current smoking has not changed from multicenter findings in the late 1990s. The persistently high prevalence of smoking suggests the inadequacy of current measures to manage tobacco use in these high-risk patients with asthma.