Is Inhaler Technique Adequately Assessed and Reported in Clinical Trials of Asthma and Chronic Obstructive Pulmonary Disease Therapy? A Systematic Review and Suggested Best Practice Checklist

Abstract

Background: Inhaled medications are central to treating asthma and chronic obstructive pulmonary disease (COPD), yet critical inhaler technique errors are made by up to 90% of patients. In the clinical research setting, recruitment of subjects with poor inhaler technique may give a false impression of both the benefits and the necessity of add-on treatments such as biologic therapies.

Objective: To assess the frequency with which inhaler technique is assessed and reliably optimized before and during patient enrollment into randomized controlled trials (RCTs) addressing the efficacy of topical therapy, and the escalation of therapy for asthma and COPD.

Methods: Systematic searches were conducted of PubMed and Embase for RCTs published in the past 10 years involving patients with a diagnosis of asthma or COPD undergoing escalation of baseline inhaled therapy (stepping up, changing, adding, switching, increasing, etc) or the introduction of biologic agents.

Results: Searches highlighted 1,014 studies, 118 of which were eligible after the removal of duplicates as well as screening and full text review. Of these, only 14 (11.9%) included accessible information in the methods section or referred to such information in online supplements or protocols concerning assessment of participants' inhaler technique. We therefore developed the proposed Best Practice Inhaler Technique Assessment and Reporting Checklist.

Conclusions: Our study identifies a concerning lack of checking and correcting inhaler technique, or at least reporting that this was undertaken, before enrollment in asthma and COPD RCTs, which may affect the conclusions drawn. Mandating the use of a standardized checklist in RCT protocols and ensuring all published RCTs report checking and correcting inhaler technique before enrollment are important next steps.

Keywords: Asthma; COPD; Checklist; Critical error; Inhaled medication; Inhaler device; Inhaler error; Inhaler technique; Obstructive airway diseases; pMDI.