Asthma-Related Health Outcomes Associated with Short-Acting β₂-Agonist Inhaler Use: An Observational UK Study as Part of the SABINA Global Program

Introduction: Patients with asthma typically increase short-acting β₂-agonists (SABA) use with worsening symptoms. Excessive SABA use may lead to a higher risk of adverse outcomes. We evaluated, in a large population cohort, an association between SABA inhaler use and asthma exacerbations and healthcare utilization.

Methods: As part of the SABINA (SABA use IN Asthma) global program, we conducted a retrospective longitudinal observational study (SABINA I) using UK primary care electronic healthcare records (Clinical Practice Research Datalink; 2007-2017) from asthma patients aged ≥ 12 years. SABA inhaler use was classified as 'high use', ≥ 3 canisters/year versus 'low use', 0-2 canisters/year. Taking into consideration all their asthma prescriptions, patients were categorized into a treatment step according to 2016 British Thoracic Society (BTS) asthma management guidelines. Multivariable regression assessed the association of SABA inhaler use by BTS treatment steps (grouped as BTS steps 1/2 and 3-5), separately, and with outcomes of exacerbations or asthma-related healthcare utilization (primary care and hospital outpatient consultations); only patients with linked hospital data were included in this analysis.

Results: Of the 574,913 patients included, 218,365 (38%) had high SABA inhaler use. Overall, 336,412 patients had linked hospital data. High SABA inhaler use was significantly associated with an increased risk of exacerbations [adjusted hazard ratio, 95% confidence interval (CI): BTS steps 1/2 = 1.20, 1.16-1.24; BTS steps 3-5 = 1.24, 1.20-1.28], asthma-related primary care consultations [adjusted incidence rate ratio (IRR), 95% CI: BTS steps 1/2 = 1.24, 1.23-1.26; BTS steps 3-5 = 1.13, 1.11-1.15], and asthma-related hospital outpatient consultations (adjusted IRR, 95% CI: BTS steps 1/2 = 1.19, 1.12-1.27; BTS steps 3-5 = 1.19, 1.13-1.26).

Conclusion: High SABA inhaler use was frequent across BTS steps and was associated with a significant increase in exacerbations and asthma-related healthcare utilization.