Fig. 5

The calibration curve of the prediction system. A Calibration curve for internal validation using data from the discovery cohort. B The calibration curve for external validation using data from the validation cohort. C The calibration curve of the internally validated nomogram for the discovery cohort using the Brier score and R-squared values. D The calibration curve of the externally validated nomogram for the discovery cohort using the Brier score and R-squared values