Effects of short- and long-acting beta-agonists on asthma exacerbations: a prospective cohort

Abstract

BACKGROUND: In asthma, short- and long-acting beta-agonists (SABAs and LABAs) should be used together with inhaled corticosteroids (ICS), and regular use is inappropriate. OBJECTIVE: To assess the relationship between patterns of use of therapy and asthma exacerbations (AEx). METHODS: Patients with asthma (6-40 years) were enrolled in France and the United Kingdom. Prescribing data, computer-assisted telephone interviews (CATIs), and text messages assessed medication use and AEx over a maximum period of 24 months. Generalized linear mixed models provided AEx risks associated with therapy. RESULTS: Among the 908 patients (median age: 20.0 years, 46.6% women, 24.5% children) answering a total of 4248 CATIs over 486 (+/-235) days, regular (ie, daily) use was more frequent for single LABAs and fixed dose combinations (FDCs) than for single ICS (75.6%, 70.1%, and 65.4% of investigated periods of use, respectively). Regular (ie, daily or almost daily) SABA use was observed for 21.1% of periods of use. Altogether, 265 patients (29.2%) experienced 1 or more AEx. The ORs for AEx risk related to regular vs no use of FDCs, single ICS, and single LABAs were 0.98 (95% CI = [0.73-1.33]), 0.90 (95% CI = [0.61-1.33]), and 1.29 (95% CI = [0.76-2.17]), respectively, after adjustment for cotherapy, sociodemographic, and disease characteristics. The OR was 2.09 (95% CI = [1.36-3.21]) in regular SABA users. CONCLUSION: Inhaled corticosteroids and FDCs were often used intermittently, whereas SABAs and LABAs could be used regularly, and exacerbations were frequent. Compared with non-users, the risk of exacerbation increased moderately under regular use of single LABAs, whereas it doubled, significantly, in regular SABA users, likely in relationship with poor overall asthma control.