Receiver operating characteristic curve: Prediction of outcome
(mortality) using serum levels of NO.
The predicted probability of mortality was assessed by using ROC curve.
We used serum levels of NO as the predictive variable and mortality as
the outcome variable. Sensitivity and specificity were calculated using
Fisher’s exact test. ROC was plotted using 1‐specificity (FPF) on X‐axis
and sensitivity (TPF) on Y‐axis for the predictor variable. A profile
with area under the curve (AUC), (C) = 0.5 shows no predictable ability
whereas (C) = 1 has a perfect predictable ability. As shown in Figure 3,
the area under the ROC curve, C = 0.96 indicated a perfect predictive
ability of mortality.