Abstract Rationale Fine particulate matter (PM2. 5) from wildfire smoke is an increasing contributor to air pollution in British Columbia (BC), Canada, and is associated with uncontrolled asthma and exacerbations. The 2023 wildfire season was BC’s most destructive on record, resulting in 2. 84 million hectares burnt. Portable high-efficiency particulate air (HEPA) cleaners can reduce indoor PM2. 5, but evidence on their long-term cost-effectiveness is limited. We extended a previous cost-effectiveness analysis to incorporate the 2023 wildfire season and examine its impact on the value of air cleaners for mitigating the health effects of wildfire smoke among patients with asthma. Methods We developed a time-varying Markov cohort model (healthcare payer perspective; 1. 5% annual discounting; 50, 000/QALY willingness-to-pay (WTP) threshold) for patients with prevalent asthma aged 40 years at baseline across 16 Health Service Delivery Areas (HSDAs) in BC. The model simulated daily transitions between health states (well-controlled asthma, not well-controlled asthma, moderate and severe exacerbations, and death) over a 10-year time horizon from 2014-2023. Daily PM2. 5 concentrations, averaged within HSDAs, were obtained from the Canadian Optimized Statistical Smoke Exposure Model (CanOSSEM), a machine learning model optimized to capture wildfire smoke exposure. We calculated the incremental cost-effectiveness ratio (ICER) of a 150 air cleaner rebate for all patients with asthma compared to a no air cleaner scenario. We evaluated costs and quality-adjusted life-years (QALYs) assuming continuous air cleaner use with a replacement unit every 5 years. Results A 150 air cleaner rebate was cost-effective in 1 out of 16 HSDAs at the WTP threshold. The ICER ranged from 44, 198/QALY in Kootenay Boundary to 88, 151/QALY in Northwest region, with a provincial average of 75, 429/QALY. Air cleaners prevented 8, 661 moderate exacerbations requiring systemic corticosteroids and 2, 090 severe exacerbations requiring an ED visit or hospitalization over the 10-year time horizon. In contrast, a 100 rebate was cost-effective in 15 out of 16 HSDAs, with ICERs ranging from 23, 230 to 52, 634/QALY and a provincial average of 44, 178/QALY. The average ICER for a 50 rebate was 12, 926/QALY. In sensitivity analyses results were most influenced by concentration-response functions for PM2. 5 and asthma control. Conclusions Over an extended time horizon that included BC’s most severe wildfire season on record, a 150 rebate on air cleaners for all patients with asthma was not cost-effective in most regions. However, at lower rebate levels and in regions with high smoke exposure, air cleaners are a high value strategy to mitigate the health effects of wildfire smoke. This abstract is funded by: None
Johnson et al. (Fri,) studied this question.