Design, Setting, Participants
Participant data from the observational COPDGene study were analyzed retrospectively. Persons aged 45-80 were eligible if they suffered from COPD, currently/previously smoked, and were either African American or Hispanic. Those experiencing a COPD flare or cardiac event less than 1 month prior to recruitment were excluded. Persons with lung disease other than COPD or asthma were ineligible. COPD was diagnosed via pulmonary function testing (PFT).