Robustifying and Selecting Cohort-Appropriate Prognostic Models under Distributional Shifts

ArXi:2604.16537v1 Announce Type: cross External validation is widely regarded as the gold standard for prognostic model evaluation. In this study, we challenge the assumption that successful external calibration guarantees model generalizability and propose two complementary strategies to improve transportability of prognostic models across cohorts. Using six real-world surgical cohorts from tertiary academic centers, we tested whether successful external calibration depends largely on similarity in covariates and outcomes between.