A network meta-analysis of the association between patient traits and response to regular dosing with ICS plus short-acting β2-agonist reliever or ICS/formoterol reliever only in mild asthma

Introduction/background Mild asthma treatment recommendations include intermittent inhaled corticosteroid (ICS)/formoterol dosing or regular ICS dosing with short-acting β2-agonist reliever. Due to the heterogeneity of asthma, identification of traits associated with improved outcomes to specific treatments would be clinically beneficial. Aims/objectives To assess the impact of patient traits on treatment outcomes of regular ICS dosing compared with intermittent ICS/formoterol dosing, a systematic literature review (SLR) and network meta-analysis (NMA) was conducted. Searches identified randomised controlled trials (RCTs) of patients with asthma aged ≥12 years, containing ≥1 regular ICS dosing or intermittent ICS/formoterol dosing treatment arm, reporting traits and outcomes of interest. Results The SLR identified 11 RCTs of mild asthma, of 14,516 patients. A total of 11 traits and 11 outcomes of interest were identified. Of these, a feasibility assessment indicated possible assessment of three traits (age, baseline lung function, smoking history) and two outcomes (exacerbation rate, change in lung function). The NMA found no significant association of any trait with any outcome with regular ICS dosing relative to intermittent ICS/formoterol dosing. Inconsistent reporting of traits and outcomes between RCTs limited analysis. Conclusions This is the first systematic analysis of associations between patient traits and differential treatment outcomes in mild asthma. Although the traits analysed were not found to significantly interact with relative treatment response, inconsistent reporting from the RCTs prevented assessment of some of the most clinically relevant traits and outcomes, such as adherence. More consistent reporting of respiratory RCTs would provide more comparable data and aid future analyses.