Table 2.

Proportion and Classification Performance of Normal and High-Risk Groups

FEV1% Predicted Value	72%	80%	95%
Number of normal group (percentage, %)	534 (95.2)	496 (88.4)	367 (65.4)
Number of high-risk group (percentage, %)	27 (4.8)	65 (11.6)	194 (34.6)
AUC	0.84	0.72	0.64
Sensitivity	0.70	0.38	0.57
Specificity	0.83	0.87	0.64
Accuracy	0.82	0.81	0.62

Notes: The sensitivity, specificity, and accuracy are calculated under the probability threshold where the Youden Index (sensitivity+specificity–1) reaches maximum.

Abbreviation: AUC, Area Under ROC Curve.