Figure 4.

Training, validation, and testing of the XGBoost model. (A,B) ROC and AUC for training and validating sets. The model was trained and validated on 10% of patients in the COPD cohort. Ten different outcomes are shown as solid lines of different colors. (C) For the test set, ROC and AUC were calculated. Tests were performed on 30% of patients in the COPD cohort. (D) Learning curve. The training set is represented by the red dashed line, while the validation set is represented by the blue dashed line. Values are expressed as the mean and 95% CIs. XGBoost, extreme gradient boosting; ROC, receiver operating characteristic; AUC, area under the curve; COPD, chronic obstructive pulmonary disorder; CI, confidence interval.