Comparison of Three Treatment Strategies in Mild Asthma: A Carbon-Utility Analysis

Background: The main types of commercially available inhalers for the management of asthma include dry powder inhalers (DPIs) and pressurized metered-dose inhalers (pMDIs). The environmental impact of pMDIs, due to hydrofluorocarbon propellants, is a growing concern. Objective: To conduct a carbon-utility analysis in mild asthma, comparing the clinical efficacy of DPIs versus pMDIs alongside their associated environmental impacts. Methods: We performed a carbon-utility analysis using data from the Novel START trial, comparing 3 treatment strategies for mild asthma: as-needed budesonide/formoterol DPI, as-needed salbutamol pMDI, and maintenance budesonide DPI plus as-needed salbutamol pMDI. We calculated carbon dioxide equivalent (kgCO₂e) emissions per quality-adjusted life year (QALY) gained. Results were compared to predefined willingness-to-emit thresholds based on health care CO₂e emissions in the United States, the European Union, and the United Kingdom. Results: As-needed budesonide/formoterol DPI had a yearly carbon footprint of 1.1 kgCO₂e and a utility of 0.936, compared with 26.2 kgCO₂e and 0.935 for as-needed salbutamol pMDI, and 17.3 kgCO₂e and 0.944 for maintenance budesonide DPI plus as-needed salbutamol pMDI. Compared with budesonide/formoterol, budesonide plus salbutamol resulted in 2192 more kgCO₂e per QALY gained, exceeding the US per capita kgCO₂e emissions in the health care sector and its 2030 target values. As-needed salbutamol was associated with higher CO₂e emissions and lower utilities than budesonide/formoterol. Conclusion: We applied to the asthma field a novel methodological approach to consider both the environmental impact and effectiveness of interventions. These findings indicate that as-needed budesonide/formoterol DPI is the preferred option when considering both carbon emissions and treatment effectiveness.