Pressurised metered dose inhalers (pMDIs) contain propellant gases with high global warming potential yet remain a cornerstone of management for asthma and chronic obstructive pulmonary disease (COPD). The aim of this study was to determine whether non-propellant alternatives of dry powder inhalers (DPIs) and soft mist inhalers (SMIs) had similar efficacy and safety. A systematic review and meta-analysis for differences in clinical outcomes and safety measures between devices was performed. No statistically significant or clinically important differences were found between inhaler types for any assessed measure. For asthma maintenance, the mean difference in peak expiratory flow rate between groups was 0.99L/min (95% confidence interval [CI] -1.11 to 3.09). For COPD, the mean difference in FEV1 between groups was 0.01L (95% CI -0.01 to 0.02). While the choice of optimal inhaler for an individual patient is a multifaceted decision, this review provides reassurance that non-pMDI devices can perform equally well.

Author JB declares personal and institutional fees from Chiesi, Boehringer Ingelheim, GSK, AstraZeneca and Sanofi for educational presentations or speaking engagements, as well as support for travelling to conferences from GSK and AstraZeneca. Author JB has participated in a study steering committee for GSK, unrelated to this topic. All other authors declare no financial or non-financial competing interests.

https://doi.org/10.26180/26065789.v2

Michael Loftus is supported by a Royal Australasian College of Physicians (RACP) Research Establishment Fellowship. Miranda Cumpston is supported by philanthropic research funding from the Walter Thomas Cottman Charitable Trust and The Phyllis Connor Memorial Trust, managed by Equity Trustees. The funders played no role in study design, data collection, analysis and interpretation of data, or the writing of this manuscript.

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