Plot of metastasis-free survival time (vertical axis) of the 19 test patients versus the rank of the estimated risk score (horizontal axis) from the five risk prediction models. The patients were numbered according to the ranks of their survival times. The patients on the left have high estimated risk scores (low ranks) and on the right have low estimated risk scores. Performance of a risk prediction model can be assessed by analyzing the relationship between survival times and risk scores (see text). For example, the horizontal line represents a cutoff at the 5 year metastasis-free time and the vertical line is the median of the training scores. A ROC curve can be constructed by enumerating all 19 vertical cutoffs and AUC can be computed (Figure 1).