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 beta 2-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 lowermiddle-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 (R) (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. PLAIN LANGUAGE SUMMARY The healthcare sector is a large emitter of greenhouse gases (GHGs); therefore, healthcare systems will need to reduce their carbon footprint to meet their carbon reduction targets. In respiratory care, the environmental impact of controller inhalers has received considerable attention due to the global warming potential of the propellants used in metered-dose inhalers. In contrast, little is known about the contribution made by short-acting b2-agonist (SABA) relievers globally, which are often the only inhaled medication used by many patients with milder asthma. The SABA use IN Asthma (SABINA) programme reported that SABA overuse (3 or more SABA canisters/year) is common and associated with an increased risk of asthma attacks. Since all inhalers have a carbon footprint, SABA overuse may result in an avoidable excess carbon footprint. Therefore, to provide a complete picture of the carbon footprint of respiratory care, we examined the contribution of SABA relievers and their potential overuse. The total SABA-related GHG emissions accounted for 70% of total inhaler-related GHG emissions, and[ 90% of prescriptions for SABA relievers for asthma were given to patients who were already overusing their SABA. Overall, SABA use/overuse is commonly observed worldwide and is likely a significant contributor to the carbon footprint of respiratory treatment. Therefore, there is an urgent need for healthcare providers to follow the latest international treatment guidelines to reduce high SABA use in respiratory care and improve patient outcomes. This, in turn, will enable healthcare systems to reduce their carbon footprint from both treatment and patient interactions.

Automated summary

This study retrospectively quantified the carbon footprint of short-acting beta 2-agonist (SABA) and controller inhalers in respiratory care, and found that SABA overuse is the main contributor to the carbon footprint of respiratory treatment. This is important for healthcare systems to reduce carbon emissions and improve patient outcomes.