Multi-Center Clean Air Randomized Controlled Trial in COPD

To be eligible, subjects must meet all these criteria:

• Age ≥ 40 years.
• Self-report of physician diagnosis of COPD.
• Spirometry confirmed airway obstruction (post-bronchodilator spirometry of forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) < 0.7) as defined by the Global Initiative for Obstructive Lung Disease (GOLD) criteria (6, 11)
• Tobacco exposure ≥ 10 pack-years. This refers to regular cigarette tobacco consumption.
• Self-reported former smoker of at least 6 months' duration. This does not include e-cigarette use.
• COPD Assessment Test (CAT) score ≥ 10, Modified Medical Research Council dyspnea scale (mMRC) ≥ 2, or history of moderate or severe exacerbation in the past 12 months (as defined by history of receiving a course of systemic corticosteroids or antibiotics for respiratory problems; or visiting an emergency department or being hospitalized for a COPD exacerbation within the past 12 months.)

To be eligible, subjects must not meet any one of these criteria:

• Living in a location other than home (e.g., long-term care facility, nursing home)
• Other chronic lung diseases, except asthma
• Condition with less than a year of life expectancy (e.g., metastatic cancer) or in hospice
• Spends >2 months per year in location other than home; or plans to change residence in the next 12 months
• Pregnant or breastfeeding
• Current air cleaner use in the home
• Inability to bring air cleaners (about 15 pounds each) into home, either by self, friend, or relative
• Deemed by the study investigator to be unable to complete study protocol, including likely lack of internet connectivity
• Participating in another interventional clinical trial