Fig. 3

Assessment and validation of the nomogram model. A ROC curve for the nomogram; B calibration plot of the nomogram. Gold line (diagonal 45-degree broken line) represents perfect prediction that nomogram-predicted probability (x-axis) matches actually observed possibility (y-axis). Blue line indicates unadjusted calibration accuracy. Red line indicates bootstrap corrected calibration accuracy. The closer the line fit is to the gold line, the better the prediction accuracy of the nomogram; C decision curves of the nomogram. Black line is the net benefit of intervening no patients. Dotted red line is the net benefit of intervening all patients. Solid red line is the net benefit of intervening patients on the basis of the nomogram. If personal threshold probability ranges from approximately 15% to 75%, the nomogram model can be beneficial for making the decision to intervene; and D clinical impact curves of the nomogram. Two horizontal axes show the correspondence between cost:benefit ratio and risk threshold. Of 1,000 patients, solid red line shows the total number of high-risk patients for each risk threshold. Solid blue line shows how many of those are with positive event. If a 20% risk threshold is used, then of 1,000 patients with AADS, about 850 are high risk, with about 380 of these developing the POHL. ROC, receiver operating characteristic; AUC, area under the receiver operating characteristic curve; CI, confidence interval; AADS, Stanford type A acute aortic dissection surgery; POHL, postoperative hyperlactatemia