Albuterol Overuse: A Marker of Psychological Distress?

Background: Albuterol overuse, 3 or more canisters per year, is associated with poor asthma control and frequent exacerbations. Objective: To describe albuterol use on symptom and symptom-free days and identify predictors of albuterol overuse and controller medication underuse. Methods: Secondary analyses of data from adults with mild asthma from the Trial of Asthma Patient Education were carried out. Based on albuterol use of 80% or more on symptom days and less than 20% on symptom-free days, participants were characterized as expected users, overusers, or underusers of albuterol. Good controller medication adherence was defined as 80% or more of prescribed doses. Data included demographic characteristics, diary data, spirometry, and scores from standardized questionnaires. Bivariate associations were examined between categorization of medication use and measured characteristics. Results: Of the 416 participants, 212 (51%) were expected users, 114 (27%) were overusers, and 90 (22%) were underusers of albuterol. No differences were observed among the user groups by demographic characteristics or lung function. Expected users demonstrated the highest asthma-related knowledge, attitudes, and efficacy. Overusers reported the greatest symptom burden, worst asthma control, and highest frequency of symptom days. Overusers also had the highest burden of depression symptoms. More frequent symptom days accounted for 15% of overuse, greater use on symptom days accounted for 31%, and greater use on symptom free days accounted for 54% of overuse. Mean controller adherence was high across all groups, and there were no differences between the groups. Conclusions: Although overusers experienced more frequent symptom days and used more albuterol on those days, most overuse was attributable to unexpected use on symptom-free days. High levels of comorbid depression were observed, particularly among overusers and among those nonadherent to controller medication.