Use of Long-Acting β-Agonists and Inhaled Steroids in Asthma: Meta-analysis of Observational Studies

Background. Current asthma guidelines recommend the use of long-acting beta-agonists (LABAs) in combination with inhaled corticosteroids (ICSs) for long-term control and prevention of symptoms in persistent asthma. Data on the risk of asthma exacerbations of LABAs in combination with ICSs, as prescribed in typical clinical practice, are very scarce. Methods. The authors conducted a systematic literature review and meta-analysis of observational studies to examine the risk of asthma exacerbations, measured as asthma-related hospitalization and/or asthma-related emergency room (ER) visits, in adults receiving LABAs plus ICSs in a fixed-dose combination compared with patients receiving ICSs alone. Results. Seven studies, all retrospective cohort studies conducted in the United States, representing approximately 96,000 patients, were included in the meta-analysis. The meta-analysis found that the use of ICSs plus LABAs was associated with a lower risk of asthma-related hospitalizations and/or ER visits than ICSs alone (odds ratio: 0.82; 95% confidence interval: 0.72-0.94). Sensitivity analyses to explore heterogeneity of endpoint definition, duration of follow-up, and patient characteristics did not significantly alter the findings. Conclusions. Overall, this systematic meta-analysis suggests that patients in clinical practice treated with a single inhaler containing ICSs plus LABAs experience fewer asthma exacerbations than similar patients treated with ICSs alone.