Figure 1

Relationship between oxygen pulse change from rest to peak exercise (ΔO ₂ Pulse) and EELV (%TLC) at peak of exercise in the study population. Horizontal and vertical interrupted lines correspond to 5.5 mL/bpm ΔO₂ Pulse value and to 75% EELV of TLC value, respectively. According to the ROC curve method, a ΔO₂ Pulse ≤ 5.5 mL/bpm was the cut-off point, which maximized sensitivity and specificity (0.640 and 0.696, respectively) with respect to EELV (% TLC) ≥ 75%, as a threshold value. Continuous line is the linear regression line.