Abstract
INTRODUCTION: Despite being linked to unfavourable outcomes, short-acting β(2)-agonists (SABAs) are still overused by a substantial proportion of patients with asthma. AIM: To analyse the prevalence and predictors of SABA overuse and exacerbations in patients with asthma in a nationwide database of prescription purchase records. MATERIAL AND METHODS: The prevalence of excessive SABA use (≥ 12 canisters) and overuse (≥ 3 canisters) was analysed among patients aged 18-64 years who purchased asthma medications in 2018. Predictors of excessive SABA use and SABA overuse were examined by quasi-Poisson regression. Negative binomial regression was used to study the association of excessive SABA use or overuse to the risk of asthma exacerbation defined as a prescription for oral corticosteroids. RESULTS: Of 91,763 patients with asthma, 42,189 (46%) were SABA users (mean age, 47 years; 58% female). Among them, 34% purchased ≥ 3 SABA canisters, and 6% purchased ≥ 12 canisters. The risk (risk ratio, 95% CI) of excessive SABA use was lower in patients with concomitant prescriptions for inhaled corticosteroids (0.41, 0.34-0.48) or inhaled corticosteroids and long-acting β(2)-agonists (0.52, 0.47-0.56), women (0.63, 0.58-0.68), and those in secondary care (0.60, 0.44-0.66); older age was associated with a higher risk of excessive SABA use (1.06, 1.03-1.10). Excessive SABA use was the strongest predictor of asthma exacerbations among all patients (3.24, 2.84-3.70) and in those with ≥ 1 exacerbation (1.60, 1.50-1.71). CONCLUSIONS: Excessive SABA use is highly prevalent in asthma management, is associated with lack of prescriptions for inhaled corticosteroids, and substantially increases the exacerbation risk.