Key points are not available for this paper at this time.
Rationale: Indoor particulate matter is associated with worse chronic obstructive pulmonary disease (COPD) outcomes. It remains unknown whether reductions of indoor pollutants improve respiratory morbidity. Objectives: To determine whether placement of active portable high-efficiency particulate air cleaners can improve respiratory morbidity in former smokers. Methods: Eligible former smokers with moderate-to-severe COPD received active or sham portable high-efficiency particulate absolute air cleaners and were followed for 6 months in this blinded randomized controlled trial. The primary outcome was 6-month change in St. George's Respiratory Questionnaire (SGRQ). Secondary outcomes were exacerbation risk, respiratory symptoms, rescue medication use, and 6-minute-walk distance (6MWD). Intention-to-treat analysis included all subjects, and per-protocol analysis included adherent participants (greater than 80% use of air cleaner). Measurements and Main Results: A total of 116 participants were randomized, of which 84.5% completed the study. There was no statistically significant difference in total SGRQ score, but the active filter group had greater reduction in SGRQ symptom subscale (β, -7.7 95% confidence interval (CI), -15.0 to -0.37) and respiratory symptoms (Breathlessness, Cough, and Sputum Scale, β, -0.8 95% CI, -1.5 to -0.1); and lower rate of moderate exacerbations (incidence rate ratio, 0.32 95% CI, 0.12-0.91) and rescue medication use (incidence rate ratio, 0.54 95% CI, 0.33-0.86) compared with sham group (all P Conclusions: This is the first environmental intervention study conducted among former smokers with COPD showing potential health benefits of portable high-efficiency particulate absolute air cleaners, particularly among those with greater adherence and spending a greater time indoors.
Hansel et al. (Fri,) studied this question.