When we increased the event rate in the CHIP cohort from 7.6% to 50% (“CHIP5050 cohort”), the behaviour of the learning curves became largely similar to the behaviour of the curves generated for the HNSCC cohort (Additional file 3, Figures 11, 12 and 13).
Figure 11  Validated AUC-values vs. events per variable, CHIP5050 cohort.
Figure 12  Relative validated AUC-values vs. events per variable, CHIP5050 cohort.
Figure 13  Optimism vs. events per variable, CHIP5050 cohort.