Ron Goldberg
Evaluating the effect of patient traits on treatment outcomes is feasible for mild and moderate to severe asthma, according to systematic review and meta-analysis findings published in Respiratory Medicine.
Although the utility of trait-based treatment has been established in severe refractory asthma, there remains a dearth of information on how this approach might be applied for mild and moderate to severe asthma. Therefore, investigators sought to identify patient traits possibly associated with improved treatment response to inhaled corticosteroid (ICS)/formoterol-containing therapy or regular ICS dosing with short-acting β2-agonist (SABA) reliever.
The investigators conducted a systematic review and meta-analysis using the Embase and MEDLINE databases from January 1998 to August 2022. The search included randomized controlled trials (RCTs) in English involving patients at least 12 years of age with asthma, reporting outcomes of at least 1 regular ICS dosing arm and/or ICS/formoterol-containing treatment arm. Accepted studies included active control or placebo, had a duration of at least 12 weeks, and aimed to assess efficacy of regular SABA dosing or ICS/formoterol-containing treatment dosing through at least 1 clinical outcome of interest.
Included RCTs were either multiregional (43.6%) or conducted in Europe (41.0%) (10.3% in the Asia Pacific region, 2.6% in North America). Sample sizes by trial ranged from 31 to 11,751. Patient mean age ranged from 34.8 years to 57.2 years, and the majority of patients were women.
Overall, 39 RCTs (N=72,740 patients) with 90 treatment arms reporting 11 outcomes and 11 traits were included in the current review. The reviewers determined at least 5 observations for each clinical outcome and each patient characteristic were necessary for any meta-analysis model.
Sufficient comparable reporting from the 28 studies of moderate-to-severe asthma revealed 5 patient traits (asthma control, smoking history, forced expiratory volume in 1 second [FEV1], body mass index [BMI], age) and 5 outcomes (time to first exacerbation, adherence, asthma control, lung function, exacerbation rate) suitable for inclusion in meta-analyses.
Comparable reporting was noted for only 3 patient traits and 2 clinical outcomes in the 11 studies recruiting patients with mild asthma.
The investigators found that among the included RCTs, 16 reported subgroups of clinical outcomes stratified by levels of patient traits.
Using the Cochrane risk of bias tool, 24 studies were judged low risk of bias and 8 had high risk of bias.
Systematic review and meta-analysis limitations include inconsistency in reporting of baseline traits and clinical outcomes.
“A systematic review of studies of regular ICS dosing with SABA or ICS/formoterol-containing treatment strategies in asthma identified consistent reporting of five traits and outcomes, allowing exploration of associations with treatment response,” the investigators concluded, adding, “Conversely, many other traits and outcomes, although being potentially relevant, were inconsistently reported and limited subgroup reporting meant analyses of treatment response for subgroups of traits was not possible.”
Roche N, Yorgancıoğlu A, Cruz AA, et al. Systematic literature review of traits and outcomes reported in randomized controlled trials of asthma with regular dosing of inhaled corticosteroids with short-acting β2-agonist reliever, as-needed ICS/formoterol, or ICS/formoterol maintenance and reliever therapy. Respir Med. Published online November 24, 2023. doi:10.1016/j.rmed.2023.107478