Difference in Mortality Risk in Elderly People with Bronchial Obstruction Diagnosed Using a Fixed Cutoff or the Lower Limit of Normal of the FEV1/FVC Ratio

Background: Whether a fixed cutoff or the lower limit of normal of the FEV1/FVC ratio should be used to diagnose bronchial obstruction is still a matter of debate. This issue is particularly important for elderly people. Objectives: We used equations applicable up to 90 years of age to evaluate the mortality of elderly people diagnosed with bronchial obstruction using either a fixed cutoff of 0.7 or the lower limit of normal (LLN). Methods: Participants in the SaRA (Salute Respiratoria nell'Anziano, Italian for "Respiratory Health in the Elderly") study were grouped as follows: FEV1/FVC ≥0.7 and ≥ LLN (n = 535: F-/L-), FEV1/FVC <0.7 but ≥ LLN (n = 118: F+/L-), and FEV1/FVC <0.7 and < LLN (n…