Association between Elevated Serum Tau Protein Level and Sepsis-Associated Encephalopathy in Patients with Severe Sepsis

Figure 2

Receiver operating characteristic (ROC) curve for the sensitivity and specificity of serum tau protein level, SOFA score, or both in predicting SAE among patients with severe sepsis. All of the parameters shown above were calculated to obtain an optimal predicted probability for the serum tau protein level and SOFA score that were set at 71.96 pg/mL and 6, respectively. The optimal predicted probabilities of the serum tau protein level, SOFA score, and a combination of the two were obtained from their respective ROC curves by maximizing the sum of the sensitivity and specificity and minimizing the overall error (square root of the sum [1 − sensitivity]² + [1 − specificity]²) and by minimizing the distance of the cutoff value to the top-left corner of the ROC curve.