Fig. 2: Receiver Operating Characteristic (ROC) curves of NIH guidelines (orange dash line), the baseline model (green line), the HRV model (red line) and the combined model (blue line).

Each curve represents the mean performance of a model across repeated experiments, with shaded areas indicating the 95% confidence interval (CI) of the AUC. The CI for NIH guidelines is not available since the risk scoring criteria of the NIH guidelines are fixed and do not need to be obtained through training. AUC area under the receiver operating characteristic curve. HRV heart rate variability. NIH National Institutes of Health.