Table 2: Mid-expiratory flow FEF 25-75% predicted and absence of ventilatory limitation (Ventilatory reserve VR > 15%).

FEF 25-75% predicted Sensitivity VR > 15% Specificity VR > 15% Positive predictive value VR > 15% Negative predictive value VR > 15%
> 50 75% 71% 90% 45%
> 40 84% 61% 88% 52%
> 30 91% 53% 87% 62%
> 20 96% 33% 83% 68%
> 10 99% 11% 80% 73%