MLP-CKD: a clinically informed deep learning framework for admission laboratory-based screening and risk stratification of uremia-associated advanced renal dysfunction.

Objective: To develop and validate a clinically informed deep learning framework for admission laboratory-based screening and risk stratification of uremia-associated advanced renal dysfunction. Methods: We propose MLP-CKD, a multi-branch feature interaction-enhanced multilayer perceptron that groups laboratory variables by clinical domain and incorporates missingness indicators to capture test-availability patterns. Adult ICU patients were extracted from MIMIC-IV, and laboratory measurements obtained within the first 24 h after ICU admission were summarized using mean, minimum, and maximum values. To prevent information leakage, only the first eligible ICU stay per patient was retained, and all model development was conducted using patient-level training, validation, and independent test splits. MLP-CKD was compared against conventional machine learning models, neural network ablation variants, and clinical rule-based baselines. Performance was assessed using discrimination, calibration, decision curve analysis, bootstrap-based 95% confidence intervals, and permutation importance. Results: On the independent patient-level test set, MLP-CKD achieved an AUC of 0.913 (95% CI: 0.907-0.919) and an AUPRC of 0.848 (95% CI: 0.838-0.859), representing the best discrimination among the primary models. Its recall and F1-score were 0.796 and 0.764, respectively. Ablation analysis showed that the Branch-only MLP achieved near-equivalent discrimination (AUC 0.913; paired-bootstrap Conclusion: MLP-CKD provides a clinically structured framework for admission laboratory-based screening and risk stratification of uremia-associated advanced renal dysfunction. The model achieved competitive discrimination and clinically plausible feature-importance patterns, with its main advantage arising from clinically informed feature grouping. Because this retrospective study used admission-window laboratory variables without a predefined future prediction horizon, MLP-CKD should be interpreted as a decision-support tool rather than as a standalone diagnostic system or a model for predicting disease onset.