Fig. 2

Illustration of the difference between outcome prediction model accuracy and its value for treatment decision making. Validation of an outcome prediction model following the AJCC checklist leads to a reliable estimate of the outcome prediction model’s accuracy if the treatment policy does not change. However, because the outcome prediction model relies on a fixed historic treatment policy, prediction accuracy does not imply value for decision making, as visualized with the gap. This gap can only be bridged with causality