Fig. 4

ROC curves of TTP to predict in-hospital mortality. The ROC curves were plotted according to the in-hospital mortality, and diagonal reference line is also shown. The X axis is 1-specificity, Y axis is sensitivity, and 16.955 h was the optimal cut-off point according to Youden’s index methodology. As shown above, ☆ points to the optimal cut-off, sensitivity is 61.5%, specificity is 91.5%, AUC (area under curve) is 0.776, with 95% CI 0.625–0.927