Comparison of time-to-event machine learning models in predicting biliary complication and mortality rate in liver transplant patients

Sci Rep. 2025 Feb 8;15(1):4768. doi: 10.1038/s41598-025-89570-4.

Abstract

Post-Liver transplantation (LT) survival rates stagnate, with biliary complications (BC) as a major cause of death. We analyzed longitudinal data with a median 19-month follow-up. BC was diagnosed with ultrasounds and MRCP. Missing data was imputed using mean and median. Data preprocessing involved feature scaling and one-hot encoding. Survival analysis used filter (Cox-P, Cox-c) and embedded (RSF, LASSO) feature selection methods. Seven survival machine learning algorithms were used: LASSO, Ridge, RSF, E-NET, GBS, C-GBS, and FS-SVM. Model development employed 5-fold cross-validation, random oversampling, and hyperparameter tuning. Random oversampling addressed data imbalance. Optimal hyperparameters were determined based on average C-index. Features importance was assessed using standardized regression coefficients and permutation importance for top models. Stability was evaluated using 5-fold cross-validation standard deviation. Finally, 1799 observations with 40 outcome predictors were included. RSF with Ridge achieved the highest performance (C-index: 0.699) for BC prediction, while RSF with RSF had the highest performance (C-index: 0.784) for mortality prediction. Top BC predictors were LT graft types, IBD in recipients, recipient's BMI, recipient's history of PVT, and previous LT history. For mortality, they were post-transplant AST, creatinine, recipient's age, post-transplant ALT, and tacrolimus consumption. We identified BC and mortality risk factors, improving decision-making and outcomes.

Keywords: Biliary complications; Liver transplantation; Machine learning; Mortality; Postoperative complications; Survival analysis.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Algorithms
  • Biliary Tract Diseases / etiology
  • Biliary Tract Diseases / mortality
  • Female
  • Humans
  • Liver Transplantation* / adverse effects
  • Machine Learning*
  • Male
  • Middle Aged
  • Postoperative Complications / mortality
  • Risk Factors
  • Survival Rate