Chronic obstructive pulmonary disease in older persons: A comparison of two spirometric definitions

Background: Among older persons, we previously endorsed a two-step spirometric definition of chronic obstructive pulmonary disease (COPD) that requires a ratio of forced expiratory volume in 1 sec to forced vital capacity (FEV1/FVC) below 70, and an FEV1 below the 5th or 10th standardized residual percentile ("SR-tile strategy"). Objective: To evaluate the clinical validity of an SR-tile strategy, compared to a current definition of COPD, as published by the Global Initiative for Obstructive Lung Disease (GOLD-COPD), in older persons. Methods: We assessed national data from 2480 persons aged 65-80 years. In separate analyses, we evaluated the association of an SR-tile strategy with mortality and respiratory symptoms, relative to GOLD-COPD. As per convention, GOLD-COPD was defined solely by an FEV1/FVC < .70, with severity staged according to FEV1 cut-points at 80 and 50 percent predicted (%Pred). Results: Among 831 participants with GOLD-COPD, the risk of death was elevated only in 179 (21.5%) of those who also had an FEV1 < 5th SR-tile; and the odds of having respiratory symptoms were elevated only in 310 (37.4%) of those who also had an FEV1 < 10th SR-tile. In contrast, GOLD-COPD staged at an FEV1 50-79%Pred led to misclassification (overestimation) in terms of 209 (66.4%) and 77 (24.6%) participants, respectively, not having an increased risk of death or likelihood of respiratory symptoms. Conclusion: Relative to an SR-tile strategy, the majority of older persons with GOLD-COPD had neither an increased risk of death nor an increased likelihood of respiratory symptoms. These results raise concerns about the clinical validity of GOLD guidelines in older persons. Published by Elsevier Ltd.