Figure 3

The ROC curve for the global score on the STS-2. The ROC Curve (blue) and reference line (green) for the STS-2 shows the sensitivity (probability of a true positive being detected) versus 1-specificity (probability of false positive) for the scale in identifying subjects with history of SA using incrementally decreased cut-off scores. Diagonal segments are produced by ties. The point of greatest separation between the ROC curve and the reference line marks the sensitivity (.667) and specificity (.774) of the optimal cut-off score.