Comparison of the Area Under the Receiver Operating Characteristic Curve and Optimal Thresholds for Sural Nerve Amplitude and the Other Nerve Fiber Function Tests.

*Two-tailed p values were calculated using a z-score obtained from testing the hypothesis that the areas under two different ROC curves are the same, according to the method of Pencina et al.†P value not applicable for sural nerve amplitude as it used as the reference to which the other tests are compared.**Optimal values were obtained by calculating the shortest distance between each variable’s ROC curve and the upper left hand corner of the ROC graph, according to the distance formula for two points in the plane, .