Respiratory drugs and macrolides prevent asthma exacerbations: A real-world investigation

Objective We investigated the real-world effectiveness of several drugs (including short- and long-acting beta-agonists [SABAs and LABAs], inhaled corticosteroids [ICS], and antibiotics) in preventing severe asthma exacerbations by carrying-out a large observational study based on the healthcare utilization databases of the Italian Lombardy Region. Methods We identified all patients aged 6–40 years who performed an Emergency Department visit for asthma during 2010–2012 as cases. To address bias due to unmeasured confounders, we implemented a case-crossover (CC) design. Addressing other specific sources of systematic errors (e.g. protopathic bias) was of particular concern in this study. Results A total of 7300 cases were included in the study. The CC odds ratios (95% confidence intervals) for current vs. past use were 0.81 (0.71, 0.92) for SABAs, 0.83 (0.72, 0.96) for ICS, 0.78 (0.66, 0.91) for LABA/ICS fixed combinations, 0.79 (0.65, 0.97) for other respiratory drugs, and 0.79 (0.69, 0.92) for macrolides antibiotics. Sensitivity analyses showed that our results were robust with respect to several sources of bias. Conclusions Our study provides evidence from the real-world clinical practice on the effectiveness of several respiratory drugs and macrolides in reducing the risk of severe asthma exacerbations.