🤖 AI Summary
To address poor generalizability of mortality prediction models in ICU settings caused by diagnostic heterogeneity, this paper proposes a diagnosis-aware transfer learning framework. First, patients are grouped by primary diagnosis; then, a shared-specific feature modeling mechanism jointly learns both population-level patterns and diagnosis-specific risk signals. The framework is implemented using generalized linear models (GLMs) and XGBoost, with decision thresholds optimized via the Youden index. Empirical evaluation on the eICU database demonstrates statistically significant improvements over baseline models—including diagnosis-specific models trained only on subset data and the APACHE IVa score—across AUC, Brier score, and calibration metrics, particularly enhancing reliability for rare diagnoses. The core contribution lies in embedding clinical diagnostic priors into the transfer learning architecture, thereby synergistically improving both diagnosis-specific interpretability and cross-diagnostic generalizability.
📝 Abstract
In the intensive care unit, the underlying causes of critical illness vary substantially across diagnoses, yet prediction models accounting for diagnostic heterogeneity have not been systematically studied. To address the gap, we evaluate transfer learning approaches for diagnosis-specific mortality prediction and apply both GLM- and XGBoost-based models to the eICU Collaborative Research Database. Our results demonstrate that transfer learning consistently outperforms models trained only on diagnosis-specific data and those using a well-known ICU severity-of-illness score, i.e., APACHE IVa, alone, while also achieving better calibration than models trained on the pooled data. Our findings also suggest that the Youden cutoff is a more appropriate decision threshold than the conventional 0.5 for binary outcomes, and that transfer learning maintains consistently high predictive performance across various cutoff criteria.