Fig. 2

Receiver operating characteristic (ROC) curve analysis of the ability of the VIS to predict EEx.

Note: The AUC for the prediction of EEx was 0.864, 95% CI: [0.828, 0.900], P < 0.001. The optimal VIS threshold for EEx prediction was 16.5, with a sensitivity of 71.54% (65.85–76.61%) and a specificity of 88.39% (81.15–93.09%)