Figure 5. Validation of the diagnostic efficacy of the random forest model. (A, B) The ROC (A) and confusion matrix (B) of the predictive model in the training dataset. (C, D) The ROC (C) and confusion matrix (D) of the predictive model in the external validation dataset. ROC, receiver operating curve. AUC, area under curve; NOA, non-obstructive azoospermia; OA, obstructive azoospermia.