Abstract
Background Exposure to air pollutants is associated with adverse chronic obstructive pulmonary disease (COPD) outcomes. Although indoor air filtration can improve outcomes, few studies have investigated indoor air filtration for improving health-related outcomes in distinct patient populations with COPD.Methods This study seeks to evaluate the effectiveness of stand-alone air filtration for reducing residential indoor particulate matter concentrations and improving health-related outcomes in a high-risk urban cohort of U.S. military Veterans with COPD in metropolitan Chicago using a long-term (1-year), randomized, single-blind, placebo-controlled, case-control trial. Participants are randomized to receive a placebo/sham unit or a normally functioning filtration unit containing HEPA, activated carbon, and zeolite media. Low-cost sensors measure particulate matter concentrations and plug load data loggers measure air cleaner operation in each home throughout the study duration. The primary outcome is physician-diagnosed exacerbations of acute COPD over the study duration. Secondary outcomes include changes in health-related quality of life (HR-QoL), assessed at recruitment and after 12-months of intervention using the COPD-specific version of the St. George’s Respiratory Questionnaire (SGRQ-C) and Veterans RAND 36-Item Health Survey (VR-36), and clinical outcomes (e.g., emergency room and unscheduled medical visits, 6-minute walk distance (6MWD), oxygen saturation) assessed at baseline, endline, and throughout the study. Housing condition assessments are also conducted to characterize participant homes and housing-related factors that may contribute to COPD exacerbation or influence the effectiveness of the intervention. Our goal is to recruit 80 participants. The study population is expected to be predominantly African American, with a significant proportion living in historically underserved, low socioeconomic status neighborhoods.Discussion Outcomes from this pragmatic, real-world trial have the potential to inform policy and practice in both healthy housing and patient medical care by evaluating the impacts of long-term use of stand-alone portable air filtration in homes of high-risk COPD patients on indoor pollutant concentrations and COPD outcomes and providing novel data on associations between housing conditions and COPD outcomes in a high-risk cohort, as well as novel insight into air cleaner operation, in this vulnerable study population.Trial Registration: ClinicalTrials.gov: NCT05913765 (retrospectively registered, June 22, 2023)