Fig. 4

A The calibration curve of the nomogram for evaluating PONV risk in the training cohort (n = 177). B The calibration curve of the nomogram for evaluating PONV risk in the validating cohort (n = 59). The horizontal axis of the calibration curve represents the predicted probability of PONV calculated by the nomogram, and the vertical axis represents the actual probability of PONV. The light blue line through the origin represents the ideal diagnosis result, and the black solid line represents the prediction result of this model. The closer the prediction solid line of the model is to the ideal diagnosis result, the better the prediction efficiency of the model. PONV, postoperative nausea and vomiting