Background: COPD is a highly morbid disease, and there is a need for a better understanding of the true prevalence. Little is known regarding overdiagnosis of COPD. According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), airflow limitation by spirometry is a key criteria for diagnosis.
Study design: Population-based survey.
Setting: Altogether, 23 sites in 20 countries worldwide were included.
Synopsis: The Burden of Obstructive Lung Disease (BOLD) study recruited community-dwelling adults who underwent questionnaires, as well as spirometry. Of the 16,717 participants, 919 self-reported a COPD diagnosis. Of these, more than half were found to not meet obstructive lung disease criteria on spirometry, and therefore were misdiagnosed: 62% when defined as forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) ratio less than the lower limit of normal and 55% when using the GOLD definition of FEV1/FVC less than 0.7. After patients with reported asthma were excluded, 34% of participants with false-positive COPD were found to be treated with respiratory medications as outpatients.
Overdiagnosis of COPD was noted to be more prevalent in high-income countries than they were in low- to middle-income countries (4.9% versus 1.9% of the participants sampled).
The self-reporting of the diagnosis of COPD is a limitation of the study because it may have artificially inflated the rate of false positives.
Bottom line: Patient-reported diagnoses of COPD should be taken with a degree of caution because of high rates of overdiagnosis and overtreatment.
Citation: Sator L et al. Overdiagnosis of COPD in subjects with unobstructed spirometry..
Dr. Gordon is a hospitalist at Maine Medical Center in Portland.