Fig. 1From: Cut-off points between pain intensities of the postoperative pain using receiver operating characteristic (ROC) curvesReceiver operating characteristic (ROC) curves of two time points. First pain assessment was performed when the patients opened their eyes spontaneously or responded well to physicians’ verbal commands to say their name after arriving at the PACU. The second pain assessment was performed 30 min after arriving at the PACUBack to article page