Greenhouse Gas Emissions from Respiratory Treatments: Results from the SABA CARBON International Study.

INTRODUCTION

Healthcare systems are looking to reduce their carbon impact. Short-acting β-agonist (SABA) overuse (≥ 3 canisters/year) is common in asthma and linked to poor outcomes; however, its environmental impact remains unknown. As part of the CARBON programme, this study retrospectively quantified the carbon footprint of SABA and controller inhalers across all respiratory indications and SABA overuse in asthma in lower-middle-income countries (LMICs), upper-middle-income countries and high-income countries across Africa, Asia Pacific, Latin America and the Middle East.

METHODS

Two data sources were utilised to evaluate the carbon contribution of inhalers to respiratory care. To quantify greenhouse gas (GHG) emissions associated with total inhaler use across all respiratory indications, inhaler sales data were obtained from IQVIA MIDAS (Q4/2018-Q3/2019) and compared by dose to prevent confounding from differences in canister actuation counts. GHG emissions associated with SABA overuse in asthma were evaluated using prescription and self-reported over-the-counter purchase data from the SABA use IN Asthma (SABINA) III study (2019-2020). Inhaler-related GHG emissions were quantified using published data and product life cycle assessments.

RESULTS

SABA accounted for > 50% of total inhaler use and inhaler-related emissions in most countries analysed. The total SABA-related emissions were estimated at 2.7 million tonnes carbon dioxide equivalents, accounting for 70% of total inhaler-related emissions. Among the countries, regions and economies analysed, per capita SABA use and associated emissions were higher in Australia, the Middle East and high-income countries. Most SABA prescriptions for asthma (> 90%) were given to patients already overusing SABA.

CONCLUSIONS

Globally, SABA use/overuse is widespread and is the greatest contributor to the carbon footprint of respiratory treatment, regardless of the economic status of countries. Implementing evidence-based treatment recommendations, personalising treatment and reducing healthcare inequities, especially in LMICs, may improve disease control and patient outcomes, thereby reducing SABA overuse and associated carbon emissions beyond SABA use alone.