Overuse of short-acting beta-agonist bronchodilators in COPD during periods of clinical stability

Background Overuse of short-acting beta-agonists (SABA) is described in asthma, but little is known about overuse of SABA in chronic obstructive pulmonary disease (COPD). Methods Prospective 3-month cohort study of patients with moderate-to-severe COPD who were provided a portable electronic inhaler sensor to monitor daily SABA use. Subjects wore a pedometer for 3 seven-day periods and were asked to complete a daily diary of symptoms and inhaler use. Overuse was defined as >8 actuations of their SABA per day while clinically stable. Results Among 32 participants, 15 overused their SABA inhaler at least once (mean 8.6 ± 5.0 puffs/day), and 6 overused their inhaler more than 50% of monitored days. Compared to those with no overuse, overusers had greater dyspnea (modified Medical Research Council Dyspnea Scale: 2.7 vs. 1.9, p = 0.02), were more likely to use home oxygen (67% vs. 29%, p = 0.04), and were more likely to be on maximal inhaled therapy (long-acting beta-agonist, long-acting antimuscarinic agent, and an inhaled steroid: 40% vs. 6%, p = 0.03), and most had completed pulmonary rehabilitation (67% vs. 0%, p < 0.001). However, 27% of overusers of SABA were not on guideline-concordant COPD therapy. Conclusions Overuse of SABA was common and associated with increased disease severity and symptoms, even though overusers were on more COPD-related inhalers and more had completed pulmonary rehabilitation. More research is needed to understand factors associated with inhaler overuse and how to improve correct inhaler use.