Health Services Burden of Undiagnosed and Overdiagnosed COPD

BACKGROUND: Misdiagnosis of COPD is common. The goal of this study was 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 aged >= 40 years from Ontario, Canada, who participated in the Canadian Obstructive Lung Disease study. The presence of physician-diagnosed COPD was ascertained for the same subjects by using linked health administrative data. Participants were then categorized into four groups: correctly diagnosed, undiagnosed, overdiagnosed, and no COPD according to either criteria. Age-and sex-standardized rates of hospitalizations, ED visits, and ambulatory care visits in each group were determined and compared. RESULTS: Of 1,403 participants, 13.7% had undiagnosed COPD, 5.1% were overdiagnosed, and 3.7% had correctly diagnosed COPD. Subjects with overdiagnosed COPD had significantly higher rates of hospitalizations, ED visits, and ambulatory care visits, and subjects with moderate to severe undiagnosed COPD had higher rates of hospitalizations, than subjects in the non-COPD population. CONCLUSIONS: Undiagnosed and overdiagnosed COPD contribute to significant health care 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 a correct diagnosis.