The Global Carbon Footprint of Asthma Inhalers: Policy Shifts Can Reduce Emissions, Analysis Group Study Finds

September 14, 2022

Asthma is a chronic respiratory condition that in many cases can be managed effectively with the use of inhalers. However, the two most popular types of inhalers – metered-dose inhalers (MDIs) and dry powder inhalers (DPIs) – differ substantially as to their greenhouse gas (GHG) emissions. Because MDIs rely on propellants, they have the potential to contribute to global warming, with a carbon footprint some 20 to 30 times higher than that of DPIs per equivalent dose. While previous studies focused on the climate impacts and costs associated with switching to low-emission inhalers on a national level, a study of the global aspect of this shift has been lacking.

A team of researchers from Analysis Group – led by Managing Principal James Signorovitch, Principal Todd Schatzki, and Manager Kalé Kponee-Shovein – has filled this gap by analyzing the global climate effects of substituting currently available DPIs for MDIs. The resulting study quantified both 2% and 5% year-over-year substitution rates of DPIs for MPIs across horizons of both 10 years and 50 years, while accounting for variables such as asthma population growth, inhaler spending, and estimates of the social cost of carbon. The results in all scenarios showed reductions in carbon dioxide equivalent (CO2e) emissions and improvements in disability-adjusted life years (DALYs). Moreover, the study found that substituting MDIs with DPIs resulted in similar patient costs in absolute terms, demonstrating that despite increases in global spending from the switch to DPIs, the differences in per-patient costs across scenarios would be “modest.” Therefore, the researchers wrote, “global efforts by environmental and health-policy decision-makers to gradually substitute currently available MDIs with DPIs for asthma control would result in substantial reductions in GHG emissions with manageable costs.”

The study, “Impact of choice of inhalers for asthma care on global carbon footprint and societal costs: a long-term economic evaluation,” was published in the Journal of Medical Economics.

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