Randomised controlled trial of a behavioural intervention to reduce exposure to PM2.5 in patients with COPD

[Display omitted] •A behavioural intervention aiming at PM2.5 exposure reduction improved COPD outcomes.•The intervention group showed greater reductions in SGRQ-C and CAT scores.•Higher intervention adherence was associated with greater reductions in CAT scores.•Regular air quality forecast checks significantly linked to CAT score reduction. Fine particulate matter (PM2.5) is a well-known risk factor for worse outcomes of chronic obstructive pulmonary disease (COPD). However, evidence-based guidance on effective personal behavioural strategies to minimise the effects of PM2.5 is limited. This study aimed to assess the effectiveness of a behavioural intervention in reducing PM2.5 exposure and improving clinical outcomes in patients with COPD. Participants were 1:1 randomised, and the intervention group received a behavioural intervention consisting of five activities, while the control group received usual care. The participants were followed up for 9 months. The primary outcomes were differences in the score of St. George’s Respiratory Questionnaire for patients with COPD (SGRQ-C) and COPD assessment test (CAT) from baseline. A total of 106 participants were enrolled and 102 completed the study. At the end of the study, the intervention group showed significant improvements in the primary outcomes compared to the control group, with a group difference of −5.9 in the reduction of total SGRQ-C (−3.4 vs. 2.5; p=0.049) and −3.8 in the CAT score (−1.2 vs. 2.7; p=0.001). Participants with good adherence to the intervention demonstrated a greater extent of improvement in CAT score and lower PM2.5 levels compared to those who had poor adherence or were in the control group. Regular checking of air quality forecasts was significantly associated with a reduction in CAT scores among all the intervention activities. Individual-level behavioural interventions can be an effective strategy for mitigating the health hazards associated with PM2.5. ClinicalTrials.gov Identifier: NCT04878367