In a Receiver Operating Characteristics (ROC) curve the sensitivity is plotted in function of the false positive rate (100-Specificity) for different cut-off points of a parameter. Each point on the ROC curve represents a sensitivity/specificity pair corresponding to a particular decision threshold. The area under the ROC curve (AUC-ROC) is a measure of how well a parameter can distinguish between two diagnostic groups (diseased/normal)
TP: true positive (number of positive cases correctly detected). TN: true negative (number of negative cases correctly detected). FP: false positive (number of negative cases incorrectly detected as positive). FN: false negative (number of positive cases incorrectly detected as negative).