Characteristics of COPD in never-smokers and ever-smokers in the general population: results from the CanCOLD study

Tan WC, Sin DD, Bourbeau J, Hernandez P, Chapman KR, Cowie R, FitzGerald JM, Marciniuk DD, Maltais F, Buist AS, Road J, Hogg JC, Kirby M, Coxson H, Hague C, Leipsic J, O’Donnell DE, Aaron SD, Group CCR. Characteristics of COPD in never-smokers and ever-smokers in the general population: results from the CanCOLD study. Thorax. 2015; 70(9): 822–9.