Background: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommends a ratio of forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) of less than 70% (FEV1/FVC < 0.7) after bronchodilators as the criteria for obstruction. However, because the FEV1/FVC ratio decreases with age, using a fixed ratio may lead to overdiagnosis of obstruction in the geriatric population. Using the lower limit of normal (LLN) as threshold for obstruction has been suggested.
Objectives: To determine the rate of overdiagnosis using the GOLD criteria compared to LLN in patients aged 60 and older. To find a better threshold with a minimal rate of over- and underdiagnosis.
Methods: The study population included adults aged 60 years and older who performed pulmonary function test (PFT) at Shaare Zedek Medical Center between 2014 and 2019 with results of FEV1/FVC < 0.7.
Results: We included 430 patients aged 60 years and older, 273 males (63.5%) and 157 females (36.5%). Mean age was 72 ± 8 years. Overdiagnosis was found in 35.6% of patients (95% confidence interval 31.1–40.3%) by using the GOLD criteria compared to the LLN. Overdiagnosis was reduced to 6.4% with the 0.65 threshold. The ideal point of the FEV1/FVC ratio where overdiagnosis and underdiagnosis were at their lowest rates was 0.638.
Conclusions: Use of the GOLD criteria for airflow obstruction may be associated with an overdiagnosis of more than 35% in patients older than 60 years. Lowering the FEV1/FVC ratio to < 0.65 might be more accurate in this population.