Abstract Rationale Indoor particulate matter (PM) is linked to worse respiratory outcomes in adults with chronic obstructive pulmonary disease (COPD). It is unclear if reducing indoor pollutants can improve respiratory health among current smokers. Objective This study aimed to assess whether a multi-component environmental intervention to improve home air quality (PM and secondhand smoke (SHS) exposure) improves respiratory morbidity among current smokers with COPD. Methods Current smokers with moderate-to-severe COPD were randomized to receive active portable HEPA air cleaners and motivational interviewing (MI) for PM and SHS reduction, respectively; or sham air cleaners without MI. The primary outcome was six-month change in Saint George’s Respiratory Questionnaire (SGRQ). Secondary outcomes were respiratory symptoms, exacerbation risk, and lung function. Main Results Among 121 randomized participants, 99 completed the study. The active intervention resulted in reduced PM levels compared to control, but no reduction in indoor SHS exposure. Those in the active arm showed a clinically and statistically significant improvement in total SGRQ score compared to control (ß -4.4 95% CI, -8.2 to -0.5; P = 0.025). Secondary analyses indicated significant improvement in respiratory symptoms (dyspnea and cough) and health status as measured by COPD Assessment Test and clinical COPD questionnaire among the active group (vs. control). There was no significant difference in FEV1 change, sputum symptoms or odds of exacerbations between groups. Conclusions This study is the first to demonstrate potential health benefits from an environmental intervention in active smokers with COPD, most likely attributable to PM reduction associated with portable HEPA air cleaner use.
Hansel et al. (Wed,) studied this question.