Fig. 2.

ROC curves for train and internal validation group in the basic model and in the extended model. A In the basic model, AUC of the train and internal validation group were 0.736 (95%CI: 0.71–0.76) and 0.736 (95%CI: 0.70–0.77). B In the basic model, AUC of the train and internal validation group were 0.756 (95%CI: 0.73–0.78) and 0.763 (95%CI: 0.73–0.80). ROC, receiver operating characteristic; AUC, area under the receiver operating characteristic