Natural History of COPD in Primary Care

Dr. Andrew Cave and Dr. Neil Drummond

Andrew Cave (
Neil Drummond (
Tyler Williamson (
Cliff Lindeman (
Anh Pham (



In Canada and around the world, Chronic Obstructive Pulmonary Disease (COPD) is a significant cause of mortality and morbidity. Recent investigation found that the national prevalence of physician diagnosed COPD in Canada is between 3-4%, meaning that roughly 1.1 to 1.4 million Canadians are affected by COPD. Many Canadians are undiagnosed and it is likely that many will remain undiagnosed unless actively sought and managed in Primary Care.


We suggest that by understanding the natural history of early COPD patients in Canada, we will be able to (1) provide a comprehensive look into the long-term treatment received by COPD patients in a primary care setting, (2) estimate the associated direct medical costs of COPD in Canada, namely costs of medications, numbers of emergency visits and hospitalizations, (3) understand which medications are used most commonly to treat COPD and their real world effectiveness, (4) report the prevalence of comorbidities and their changes over time.


We will investigate the natural history of a nationwide sample of COPD patients using the Canadian Primary Care Sentinel Surveillance Network (CPCSSN) database. Using the database, we have previously described COPD in primary care in Canada at a point in time (2012). Since our first study, more variables have become available to the system and there is an excellent opportunity to, not only describe a cohort of COPD patients, but also to follow them over time identifying characteristics and their relationship with outcomes such as exacerbations, hospitalisation etc. Patient subjects will be followed in the database from 2009 when data collection started and then forward from today. Recorded variables that we believe to be important in establishing the natural history of the cohort include: age at detection, medication past and current, changes and adherence to therapy (prescription frequency), comorbidities, exacerbations, supplemental oxygen use, indicators of increased direct healthcare costs (increased emergency visits, hospitalization and referrals), laboratory investigations, smoking status, employment status and at risk occupations.