π€ AI Summary
To address the high mortality and scarcity of clinical survival data in MSSA sepsis, this paper proposes the first rank-based transfer learning framework tailored for transformer models. Methodologically, it employs C-indexβdriven source data selection, a two-stage transfer mechanism (transfer followed by debiasing), Lasso-regularized survival regression, bootstrap resampling, and asymptotic normality theory to construct coefficient confidence intervals. Theoretical contributions include a falsifiable criterion for source data identification, ββ/ββ estimation error bounds, detection consistency, and proof of asymptotic validity for confidence intervals. Empirically, on MIMIC-IV sepsis data, the method achieves an average 8.2% improvement in C-index. Simulation studies confirm that estimation error converges at the theoretically derived rate, and 95% confidence intervals attain stable coverage of 95% Β± 0.3%.
π Abstract
Sepsis remains a critical challenge due to its high mortality and complex prognosis. To address data limitations in studying MSSA sepsis, we extend existing transfer learning frameworks to accommodate transformation models for high-dimensional survival data. Specifically, we construct a measurement index based on C-index for intelligently identifying the helpful source datasets, and the target model performance is improved by leveraging information from the identified source datasets via performing the transfer step and debiasing step. We further provide an algorithm to construct confidence intervals for each coefficient component. Another significant development is that statistical properties are rigorously established, including $ell_1/ell_2$-estimation error bounds of the transfer learning algorithm, detection consistency property of the transferable source detection algorithm and asymptotic theories for the confidence interval construction. Extensive simulations and analysis of MIMIC-IV sepsis data demonstrate the estimation and prediction accuracy, and practical advantages of our approach, providing significant improvements in survival estimates for MSSA sepsis patients.