Exacerbation-Related Greenhouse Gas (GHG) Emissions of Severe Asthma Along The Care Pathway

<bold>Objectives:</bold> Describe the exacerbation-related GHG emissions of severe asthma (SA) along the care pathway in the United Kingdom. <bold>Methods:</bold> This retrospective observational study used medical records extracted from Clinical Practice Research Datalink Aurum, Hospital Episode Statistics and CO₂ Equivalent Emissions data. Patients ≥12 years-old with SA (having a validated asthma diagnosis code and a high-dose ICS with another controller medication) from 01/01/2007-31/03/2022 were included. Severe uncontrolled asthma (SUA) and regular specialist care (RSC) were defined as having ≥2 exacerbations and ≥2 respiratory specialist visits per year respectively. Five pathways according to their order of transition from SA to SUA and/or receiving RSC and their exacerbation-related GHG emissions were described, excluding emissions relating to inhaler medications. <bold>Results:</bold> 93,054 patients with SA were included (mean [SD] age 51.2[17.7], 66% female). In pathways 2 to 5, exacerbation-related GHG emissions increased after SA progressed to SUA and/or dropped after transitioning to RSC. Hospitalisations were the major contributor (Figure 1). <bold>Conclusions:</bold> Exacerbation-related GHG emissions were higher for SUA patients. Receiving RSC for patients with SA is known to improve patient outcomes. Our findings suggest it could also reduce exacerbation-related GHG emissions. Interventions that reduce hospital admissions should be prioritized. <fig><object-id>erj;64/suppl_68/PA1281/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>