Table 3.

Results from the ROC analysis of IL-8 for the discrimination between mild and severe groups.

	AUC (95% CI)	P	Optimal cut-off	Sensitivity %	Specificity %	PPV	NPV
IL-8 (2nd day)	0.92(0.80–1.00)	.001	25.4	88.9	88.2	80.0	93.8
IL-8 (3rd day)	0.80(0.58–1.00)	.014	14.5	88.9	55.8	53.3	90.9

AUC: Area Under the Curve; CI: Confidence Intervals; PPV: Positive Predictive Value; NPV: Negative Predictive Value.