Does a single post–bronchodilator spirometry assessment definitely diagnose COPD in patients with mild to moderate airway obstruction? Probably not, according to a study published in the journal American Journal of Respiratory and Critical Care Medicine that looked at more than 7,000 participants in two study groups. Shawn D. Aaron and colleagues found that over four to five years, diagnostic instability (a positive or negative diagnosis that switches and then reverts to the original diagnosis) was as high as 19.5 percent and diagnostic reversal was as high as 27.2 percent in patients with mild to moderate airway obstruction. As might be expected, patients closest to the diagnostic threshold were most likely to experience diagnostic instability, while patients who quit smoking were most likely to experience a diagnostic reversal.

Noting that COPD guidelines “are silent on the merits of postponing” a COPD diagnosis, the authors say their finding suggest that taking a “wait and retest” approach with patients close to the diagnostic thresholds may avoid the over–diagnosis and under–diagnosis of COPD.

The article is titled, “Diagnostic Instability and Reversals of Chronic Obstructive Pulmonary Disease Diagnosis in Individuals with Mild to Moderate Airflow Obstruction.”