Widespread false diagnosis of COPD is exposing patients to unnecessary medication risks, study suggests

In an analysis of almost 1,000 patients reporting a diagnosis of COPD, post-bronchodilator spirometry revealed a false-positive diagnosis in 62% of cases. 

Researchers from Europe, the US and South Africa analysed data from 16,177 patients in 20 countries who participated in the BOLD Study between 2003 and 2012.

Among the 919 patients (5.7%) who reported a previous diagnosis of COPD, 569 (61.9%) were found not to have respiratory obstruction, as defined by a post-bronchodilator FEV₁/FVC greater than the lower limit of normal. The rate of overdiagnosis was similar when defined by a fixed-ratio criterion of FEV₁/FVC less than 0.7 (55.3%). 

The study authors acknowledge that the diagnosis of COPD was self-reported by patients, which could have led to overestimation.

Among the patients incorrectly diagnosed with COPD, 45.7% reported that they were using respiratory medication, most often inhaled corticosteroids.

The site-specific prevalence of false-positive COPD varied from 1.9% in low- to middle-income countries to 4.9% in high-income countries. In multivariate analysis, overdiagnosis was more common among women, and was associated with higher education, former and current smoking, presence of wheeze, cough and phlegm, and concomitant medical diagnosis of asthma or heart disease. 

Post-bronchodilator spirometry is a mandatory diagnostic criterion for COPD in national and international guidelines, leading the researchers to speculate that healthcare professionals are either not aware of COPD guidelines or do not use them for decision-making. They urge 'every effort to be made to encourage the use of high-quality spirometry to support the diagnosis for COPD and appropriate use of medications'.