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

BACKGROUND

In asthma, short- and long-acting β-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.