Health services burden of undiagnosed and overdiagnosed COPD

Background — Misdiagnosis of chronic obstructive pulmonary disease (COPD) is common. We aimed to quantify the health services burden of undiagnosed and overdiagnosed COPD in a real world, North American population.

Methods — A population-based cohort study was conducted. Presence of COPD using spirometry was ascertained in randomly selected adults age 40 or older from Ontario, Canada who participated in the Canadian Obstructive Lung Disease study. Presence of physician diagnosed COPD was ascertained for the same people using linked health administrative data. Participants were then categorized into four groups: correctly diagnosed, undiagnosed, overdiagnosed and no COPD by either criteria. Age and sex standardized rates of hospitalizations, emergency department visits and ambulatory care visits in each group were determined and compared.

Results — Of 1,403 participants, 13.7% had undiagnosed, 5.1% overdiagnosed, and 3.7% correctly diagnosed COPD. People with overdiagnosed COPD had significantly higher rates of hospitalizations, emergency department visits and ambulatory care visits, and people with moderate to severe undiagnosed COPD had higher rates of hospitalizations, than people in the non-COPD population.

Conclusions — Undiagnosed and overdiagnosed COPD contribute to significant healthcare burden. Given that misdiagnosed COPD was fivefold more common than correctly diagnosed COPD, these findings point to a substantial misdiagnosis-associated burden of disease that might be prevented, at least in part, with correct diagnosis.