Instability in the COPD Diagnosis upon Repeat Testing Vary with the Definition of COPD

<div><p>Background</p><p>A low FEV₁/FVC from post-bronchodilator spirometry is required to diagnose COPD. Both the FEV₁ and the FVC can vary over time; therefore, individuals can be given a diagnosis of mild COPD at one visit, but have normal spirometry during the next appointment, even without an intervention.</p><p>Methods</p><p>We analyzed two population-based surveys of adults with spirometry carried out for the same individuals 5-9 years after their baseline examination. We determined the factors associated with a change in the spirometry interpretation from one exam to the next utilizing different criteria commonly used to diagnose COPD.</p><p>Results</p><p>The rate of an inconsistent diagnosis of mild COPD was 11.7% using FEV₁/FVC <0.70, 5.9% using FEV₁/FEV₆ 1.</p><p>Conclusions</p><p>Using FEV₁/FEV₆ </p>