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

Background There is limited data on the risk factors and phenotypical characteristics associated with spirometrically confirmed COPD in never-smokers in the general population. Aims To compare the characteristics associated with COPD by gender and by severity of airway obstruction in never-smokers and in ever-smokers. Method We analysed the data from 5176 adults aged 40 years and older who participated in the initial cross-sectional phase of the population-based, prospective, multisite Canadian Cohort of Obstructive Lung Disease study. Never-smokers were defined as those with a lifetime exposure of 1 /FVC Results The prevalence of COPD (FEV 1 /FVC Conclusions The study confirmed the substantial burden of COPD among never-smokers, defined the common and gender-specific risk factors for COPD in never-smokers and provided early insight into potential phenotypical differences in COPD between lifelong never-smokers and ever-smokers. Trial registration number NCT00920348 (ClinicalTrials.gov); study ID number: IRO-93326.