Lifetime risk of developing chronic obstructive pulmonary disease: a longitudinal population study.

BACKGROUND: Although chronic obstructive pulmonary disease (COPD) is one of the most deadly, prevalent, and costly chronic diseases, no comprehensive estimates of the risk of developing COPD in the general population have been published. We aimed to quantify the lifetime risk of developing physician-diagnosed COPD in a large, multicultural North American population.
METHODS: We did a retrospective longitudinal cohort study using population-based health administrative data from Ontario, Canada (total population roughly 13 million). All individuals free of COPD in 1996 were monitored for up to 14 years for three possible outcomes; diagnosis of COPD by a physician, reached 80 years of age, or death. COPD was identified with a previously validated case definition based on COPD health services claims. The cumulative incidence of physician-diagnosed COPD over a lifetime adjusted for the competing risk of death was calculated by a modified survival analysis technique. Results were stratified by sex, socioeconomic status, and whether individuals lived in a rural or urban setting.
FINDINGS: A total of 579,466 individuals were diagnosed with COPD by a physician over the study period. The overall lifetime risk of physician-diagnosed COPD at age 80 years was 27·6%. Lifetime risk was higher in men than in women (29·7%vs 25·6%), individuals of lower socioeconomic status than in those of higher socioeconomic status (32·1%vs 23·0%), and individuals who lived in a rural setting than in those who lived in an urban setting (32·4%vs 26·7%).
INTERPRETATION: About one in four individuals are likely to be diagnosed and receive medical attention for COPD during their lifetime. Clinical evidence-based approaches, public health action, and more research are needed to identify effective strategies to prevent COPD and ensure that those with the disease have the highest quality of life possible. FUNDING: Government of Ontario, Canada.