Subjects with Discordant Airways Obstruction: Lost between Spirometric Definitions of COPD.

Background. Since the FEV1/FVC ratio declines with age, using the fixed ratio of 0.70 leads to overdiagnosis of COPD in older populations and underdiagnosis among young adults. Objective. To evaluate whether discordant obstructive cases (FEV1/FVC < 0.70 but ≥LLN) are a healthy population or have clinical features that would place them at increased risk. Methods. We used post-bronchodilator spirometry data from the population-based Austrian Burden of Obstructive Lung Disease (BOLD) study. Those with post-bronchodilator FEV1/FVC ratio