Fig. 4

Comparison of ROC curves. A Red line indicated model using AKI class. Blue line indicated model using AKI stage. B Red line indicated model using AKI class and adjusted variables. Blue line indicated model using AKI class and adjusted variables. Adjusted variables included age, body mass index, male sex, SAPS II score, SOFA score, and Elixhauser comorbidity score. DeLong test was used to compare the AUC values of models. ROC, receiver operating characteristic; AKI, acute kidney injury; SAPS II, Simplified Acute Physiology Score II; SOFA, Sequential Organ Failure Assessment; AUC, area under the ROC curve