ROC and Kaplan-Meier curves for 28-day mortality in septic patients.

A: The ROC Curve of FMD in predicting 28-day mortality in patients with sepsis. The area under the curve was 0.764 (0.627–0.869). The value of -1% was chosen as the cutoff point for FMD (sensibility of 78.7%, specificity of 75%, positive likelihood ratio of 3.15 and negative likelihood ratio of 0.28). B: Kaplan-Meier curve showing 28-day mortality in septic patients with FMD≤ -1% (mean survival time of 13.4 days) and FMD> -1% (mean survival time of 25.4 days). The survival curves were compared using log-rank test, p = 0.001. C: The ROC Curve of RMSSD in predicting 28-day mortality in patients with sepsis. The area under the curve was 0.784 (0.656–0.881). The value of 10.8 ms was chosen as the cutoff point for RMSSD (sensibility of 77.1%, specificity of 73.9%, positive likelihood ratio of 2.96 and negative likelihood ratio of 0.31. D: RMSSD≤10.8ms (mean survival time of 13.2 days) and RMSSD> 10.8ms (mean survival time 23.1 days). The survival curves were compared using log-rank test, p> 0.01, showing higher mortality in both lower cut-off.