Interventions to reduce indoor particulate matter exposure in patients with chronic obstructive pulmonary disease: a scoping review

Abstract

Abstract Background Indoor particulate matter (PM) exposure accelerates lung function decline, increases exacerbations, and raises mortality among patients with chronic obstructive pulmonary disease (COPD). Many interventions aim to reduce this exposure, but they differ in design, delivery, and target, and no framework has organized them by the point of the causal chain at which they act. This scoping review aimed to classify these interventions, map them onto the Driving forces–Pressures–State–Exposure–Effect–Action (DPSEEA) framework, and summarize the outcomes reported. Methods We followed the Joanna Briggs Institute scoping review methodology and reported according to PRISMA-ScR. We searched ten databases (PubMed, Embase, Scopus, CINAHL, Web of Science, the Cochrane Library, and four Chinese databases) from inception to 9 August 2026. Two reviewers screened records independently and charted data with a standardized coding manual (agreement, κ = 0.91). We classified each intervention by its primary DPSEEA stage. Results Sixteen studies met the inclusion criteria. Three intervention types emerged: air purification ( n = 11), multi-component behavioral interventions ( n = 5) and policy-level interventions ( n = 4). The interventions acted at four of the six DPSEEA stages: air purification and behavioral interventions addressed the State and Exposure stages, whereas the four policy-level interventions acted at the Driving forces ( n = 2) and Pressures ( n = 2) stages. No intervention addressed the Effect stage, and no study set out to test coordinated action across stages. Outcome measures fell into four domains, covering exposure, clinical and physiological, health-related quality of life, and behavioral indicators, and studies defined them inconsistently. Conclusion The review classified interventions to reduce indoor PM exposure in COPD into three types and located them at four of the six DPSEEA stages, most midway along the causal chain. Because no study tested coordinated action across stages, the evidence cannot show whether combining upstream and downstream measures adds benefit. Two priorities follow: upstream policy measures on household energy and housing should be evaluated with health outcomes, since they are the least studied and the most likely to be equitable; and studies need longer follow-up and a common set of outcome indicators. Equity-focused research is needed most in low-income, biomass-dependent regions.