Table 3.

Calibration and discrimination of the models

Model	Internal validation (fivefold cross-validation on the training set)				External validation on the validation set
	P value of Hosmer–Lemeshow test		Area under the ROC curve		Hosmer–Lemeshow test		Area under the ROC curve
	Mean	Standard deviation	Mean	Standard deviation	Test statistic C	P value
Original SAPS II	0.001	0.001	0.8591	0.0058	1162.9	<0.0001	0.8575
Customized SAPS II	0.6280	0.1422	0.8562	0.0058	6.41	0.7794	0.8575
Expanded SAPS II	0.2754	0.3832	0.8797	0.0054	6.04	0.8116	0.8787

ROC, receiver operating characteristic; SAPS, Simplified Acute Physiology Score.