The Prevalence of Chronic Obstructive Pulmonary Disease (COPD) and the Heterogeneity of Risk Factors in the Canadian Population: Results from the Canadian Obstructive Lung Disease (COLD) Study.

This study reports the population prevalence of COPD in nine urban cities which collectively represent the majority of the Canadian population and demonstrates that heterogeneity in prevalence among sites is substantially explained by variation in associated risk factors for COPD.