(77) Real-World Impact of Non-Clinical Inhaler Switching on Asthma or COPD Patients: A Systematic Review

Publication Number: 751

Background: Switching inhaler regimens can be driven by poor disease control, but also by non-clinical factors, such as cost and environmental impact. However, the consequences of switching for non-clinical reasons are largely unclear, and studies have reported opposing outcomes.

Objectives: To systematically review the real-world consequences of switching inhalers for non-clinical reasons in asthma and/or COPD patients.

Methods: Embase, MEDLINE, EBM Reviews and EconLit were searched to 21st November 2020. Conference searches and reference checking were also performed. Real-world studies of asthma and/or COPD patients undergoing a switch in inhaler regimen for any reason apart from clinical need were included. Clinical, humanistic and economic outcomes were included, and results from higher quality (matched comparative) studies were prioritised. Studies were categorised based on whether patients had consented to the switch or not. Two reviewers screened and extracted data and performed risk of bias assessment. This study was registered on PROSPERO (CRD42021230427).

Results: 8,958 records were screened and 21 studies were included. Five matched studies (six datasets) reported on symptom control at 12 months. In five datasets where it was unclear whether patients had consented to the switch, improved disease control was reported following switching (adjusted odds ratio (aOR) 1.221, 95% confidence interval (CI) 0.95 to 1.57 (N=2,568); aOR 1.26, 95% CI 1.05 to 1.52 (N=1,958); aOR 1.32, 95% CI 0.79 to 2.17 (N=480); aOR 1.45, 95% CI 1.02 to 2.04 (N=996); aOR 1.56, 95% CI 1.14 to 2.14 (N=1,528)). In one dataset where patients had not consented to the switch, significantly worsened disease control was reported following switching (aOR 0.29, 95% CI 0.19 to 0.44; N=1,648). Similar contrasting directions of effect were observed for other outcomes, including exacerbations, reliever use, rescue medication use, hospitalisations, healthcare visits, drug costs and costs of care. Risk of bias was generally high, and study designs were heterogeneous.

Conclusions: Switching inhalers can have highly variable clinical, humanistic and economic consequences. Current evidence suggests that inhaler switching without engaging the patient in the process should be avoided. Further research is needed to determine, a priori, the appropriate conditions for switching.