Evaluation of system performance by random forest
Patient groups were randomly divided into training and test sets by the following ratios: 75%:25%, 70%:30%, 60%:40%, and 50%:50%. The model was developed using cases from the training set. On the test set, the same model was applied. The area under the curve (AUC) of the ROC analyses in each set was used to determine the DP of the estimator derived from each model.