Chronic obstructive pulmonary disease (COPD) is prone to false positive diagnosis, according to an article published in CHEST. Misdiagnosed individuals may be at risk for adverse side effects from respiratory medication.
This study included 16,177 participants from 20 countries enlisted in the Burden of Obstructive Lung Disease (BOLD) study, an ongoing population-based survey that uses questionnaires. COPD false positive diagnosis was defined as unobstructed postbronchodilator spirometry (forced expiratory volume in 1 second/forced vital capacity>lower limit of normal [FEV1/FVC>LLN]) following a COPD diagnosis. A ratio of FEV1/FVC <0.7 was used as a fixed value in further analyses. Comparisons among baseline characteristics were performed using the t-test, Mann-Whitney U-test, and Chi-square test.
Of the study population, 5.7% (n=919) had been diagnosed with COPD. In this group, 61.9% (n=569) showed unobstructed postbronchodilator spirometry, indicating a false positive diagnosis. There was a 45.7% rate of reported respiratory medication use in the last 12 months in those individuals with a false positive diagnosis, and a 34.4% rate after excluding those with asthma. The fixed ratio FEV1/FVC <0.7 yielded a similar false positive rate of 55.3%. In a subgroup analysis excluding those who reported a chronic bronchitis or emphysema diagnosis, 37.7% showed no limitation in airflow. False positive COPD diagnosis was more common in high-income countries (4.9%) than in low-middle income countries (1.9%). Overdiagnosis was also more likely in individuals with higher education levels, wheeze, concomitant heart disease or asthma, cough with phlegm, smoking (current or former), and female sex.
These results are limited by potential overestimation of defining previous COPD diagnosis as self-reported physician-diagnosed COPD.
The researchers concluded that “Every effort should be made to encourage the use of high-quality spirometry to support the diagnosis for COPD and appropriate use of medications.”
Disclosures: The BOLD program received funding from Aventis, AstraZeneca, Boehringer-Ingelheim, Chiesi, GlaxoSmithKline, Merck, Novartis, Pfizer, and Schering-Plough. Some authors report pharmaceutical financial associations. For a full list of author disclosures, please see the reference.
Sator L, Horner A, Studnicka M, et al; for the BOLD Collaborative Research Group. Overdiagnosis of COPD in subjects with unobstructed spirometry – a BOLD analysis [published online January 31, 2019]. CHEST. doi:10.1016/j.chest.2019.01.015