Cohort Profile

CanCOLD is the first observational cohort specific to COPD having recruited its participants from the general population rather than more convenient recruitment in clinical settings. This strategy better mirrors prevalent COPD populations at large and provides proper representation of typically underrepresented groups in COPD studies; early disease, female population, individuals who have never smoked (up to 30% of the COPD population) and those with physician undiagnosed disease (up to 70% of the COPD population).

CanCOLD originated from the cross-sectional Burden of Obstructive Lung Disease (BOLD) study, an international initiative measuring the prevalence of COPD and its risk factors in different regions around the world, which included a data collection site in Vancouver, Canada. Expanding on this initiative nationally, the Canadian Obstructive Lung Disease (COLD) population-based prevalence study was established by randomly sampling a total of 6,551 non-institutionalized men and women aged ≥ 40 years from 9 Canadian cities: Vancouver, Montreal, Calgary, Quebec, Halifax, Toronto, Kingston, Saskatoon, and Ottawa.

With the aim of establishing a longitudinal population-based COPD cohort in Canada, COLD study participants within four target subsets were contacted to enroll in CanCOLD:

1. Individuals with mild COPD (GOLD 1; post-bronchodilator FEV1/FVC<0.70 and FEV1≥80% predicted)
2. Individuals with moderate-severe COPD (GOLD ≥2; post-bronchodilator FEV1/FVC<0.70 and FEV1<80% predicted)
3. Sex and age matched (±2 years) ever-smokers without COPD
4. Sex and age matched (±2 years) never-smokers without COPD

Data Collection Waves

At each data collection wave, trained CanCOLD research staff collect a deep pool of information that can be queried to address research questions related to COPD. A wide range of physical measures and assessment tools are used including anthropometric measures, validated questionnaires, blood samples, pulmonary function tests, cardiopulmonary exercise test (CPET) and multidetector computerized tomography scan (CT Scan).

Respiratory health is additionally evaluated by telephone contact every 3 months, when participants respond to a COPD exacerbation questionnaire, with questions on symptom changes, medication and health service use.

CanCOLD data can be linked to information held in provincial administrative and vital statistics databases such as health care utilization, medication intake, and cause of mortality. Finally, in order to assess the relationship of chronic respiratory disease development and progression with environmental factors such as ambient air pollution exposure and climate and weather events, data distributed by the Canadian Urban Environmental Health Research Consortium (CANUE) is linked to CanCOLD data.

Data Overview

At each data collection wave, trained CanCOLD research staff collect a deep pool of information that can be queried to address research questions related to COPD. Respiratory health is additionally evaluated by telephone contact every 3 months, when participants respond to a COPD exacerbation questionnaire. CanCOLD data can be linked to information held in provincial administrative and vital statistics databases as well as environmental exposure data distributed by the Canadian Urban Environmental Health Research Consortium (CANUE) is linked to CanCOLD data.

To explore all variables collected by the CanCOLD Study, please visit our Data Portal