FIGURE 3.

Receiver operating characteristic (ROC) curves and calculated area under the curves (AUC). (A) Development study of the Delphi score (dotted line, ROC curve of the logistic regression model; solid line, ROC curve of the Delphi score). (B) Validation study of the Delphi score. Delphi score is useful to distinguish patients with high risk of postoperative delirium from those with low risk. The cut-off value of the Delphi score corresponding to the optimal trade-off between sensitivity and specificity is 6.5. AUC = area under the curves; ROC = receiver operating characteristic.