Receiver operating characteristic curve

The receiver operating characteristic curve (ROC) plots sensitivity against 1- specificity (ie, the false positive rate). Cutoff values for the diagnostic test (such as serum ALT concentrations) vary along the length of the black curve, reflecting the interchange between sensitivity and specificity. The area under the ROC curve represents the accuracy of the test. A test that performs no better than chance would be represented by a straight line (red line) with an area under the ROC of 0.5. A near perfect test would have a rectangular configuration (blue line) with an area under the ROC approaching 1.00.