COPD

Study: Current COPD Guidelines Frequently Cause Misdiagnosis

Current guidelines for the treatment and diagnosis of chronic obstructive pulmonary disease (COPD) cause overdiagnosis in older men and underdiagnosis in younger women, according to recent research.

COPD is diagnosed using the ratio of forced expiratory volume in 1 second (FEV1) divided by the forced vital capacity (FVC). While standards for defining the lower limits of normal (LLN) for FEV1/FVC that take into account age, height, sex, and ethnicity are established and agreed upon, they do no match guidelines created for the Global Initiative for Obstructive Lung Disease (GOLD) in 2001.
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GOLD standards state that airway obstruction is defined as a FEV1/FVC of <0.7, regardless of other factors. This definition is widely used within the United States, Europe, and Australia.

While the 2006 version of the GOLD standards acknowledged that use of LLN would reduce overdiagnosis in older patients, they maintain that use of a fixed ratio is optimal because of its benefits to ease-of-use.  

Authors of the current research found that a significant portion of those diagnosed under GOLD standards could be misdiagnosed. For example, when researchers applied GOLD standards to patients in the UK and Wales, they found that 22% of individuals older than 40 met the criteria for COPD, while only 13% of the same individuals met the LLN criteria for diagnosis.

“Misdiagnosing patients may lead to poorer outcomes because of adverse effects of inappropriate medication or incorrect treatment,” the authors wrote.

While overdiagnosis was prevalent in men over 40 years old, researchers also found that the GOLD standards underdiagnose a significant amount of young women. “This means that patients with the most potential gain from prevention strategies are denied such interventions and will potentially go on to develop more serious disease before COPD is diagnosed” they noted.

“We argue that clinicians should use the LLN instead when assessing patients for COPD. Adoption of this criterion, which is programmed into most spirometry software, will help to improve patient care through more accurate diagnosis of obstructive airflow diseases as well as leading to other investigations for alternative diagnoses when appropriate,” they concluded.

—Michael Potts

Reference:

Miller MR, Levy ML. Chronic obstructive pulmonary disease: missed diagnosis versus misdiagnosis. BMJ. 2015;351:h3021.