Chronic obstructive pulmonary disease as a risk factor in primary care: a Canadian retrospective cohort study

Chronic obstructive pulmonary disease (COPD) is a complex disease that is predicted to be the third most common cause of death by 2030. In Canada, the care and management of chronic conditions is largely provided by primary care providers. Although there is emerging research and initiatives that describe the prevalence of COPD in Canadian primary care settings, to our knowledge, there have been no efforts to use a large pan-Canadian database to analyze COPD as a risk factor for other common chronic conditions managed in primary care. We report the risk of developing comorbidities after the onset of COPD, that is, the extent to which COPD is a risk factor for developing common chronic conditions (heart failure, depression, anxiety, coronary artery disease, diabetes, anemia, hypertension, ischemic heart disease, underweight, and osteoporosis). After adjusting for age, sex, urban vs rural residence, and smoking status, the relative risks for patients with COPD at baseline were significantly higher for subsequent incidence of anemia, anxiety, diabetes, depression, heart failure, ischemic heart disease, lung cancer, osteoporosis, sleep apnea, underweight, and hypertension than patients without COPD. Using a cut-point of a 200% increase in relative risk as indicative of particular clinical relevance, COPD has a statistically and clinically significant association with developing lung cancer, becoming underweight, and developing heart failure.