Usage patterns of short-acting β2-agonists and inhaled corticosteroids in asthma: a targeted literature review

Abstract Despite the availability of effective asthma treatments, some patients are poorly controlled due to over-reliance on short-acting β2-agonists (SABAs) and underuse of inhaled corticosteroids (ICS). To identify patient characteristics and outcomes associated with SABA over-reliance and ICS underuse, we conducted a targeted literature review of the quantitative evidence on asthma medication use. Articles evaluating SABA and/or ICS use in asthma patients (aged ≥12 years), published between January 2012 and March 2018 were identified using MEDLINE and EMBASE. We observed that studies classified SABA usage as ‘overuse’, ‘high use’, ‘excess use’, ‘extreme overuse’, ‘suboptimal use’, and ‘inappropriate use’. Multiple thresholds were used to define overuse of SABA (≥3 to ≥12 canisters/year). SABA over-reliance was prevalent, with approximately 20% of adults using ≥3 canisters/year (≥12 inhalations/week). Similarly, inappropriate ICS use, classified as ‘suboptimal’, ‘high use’, ‘underuse’, and ‘unlicensed use’, was defined by varying thresholds. Specific patient populations, such as older adults, smokers, and patients with low income, were more susceptible to SABA over-reliance and ICS underuse. Over-reliance on SABAs was associated with increased risk of severe exacerbations, asthma-related hospitalizations, emergency department visits, and asthma-related costs. These findings emphasize the prevalence and related burden of SABA over-reliance at the potential expense of appropriate ICS use.