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Bibliographic Details
Main Authors: Cui, Wenhai, Su, Wen, Zhao, Xingqiu
Format: Preprint
Published: 2026
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Online Access:https://arxiv.org/abs/2603.05568
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author Cui, Wenhai
Su, Wen
Zhao, Xingqiu
author_facet Cui, Wenhai
Su, Wen
Zhao, Xingqiu
contents Integrative analysis of multiple datasets for estimating optimal individualized treatment rules (ITRs) can enhance decision efficiency. A central challenge is posterior shift, wherein the conditional distribution of potential outcomes given covariates differs between source and target populations. We propose a prior information-based distributionally robust ITR (PDRO-ITR) that maximizes the worst-case policy value over a covariate-dependent distributional uncertainty set, ensuring robust performance under posterior shift. The uncertainty set is constructed as an individualized combination of source distributions, with weights combining prior source-membership probabilities and deviation terms constrained to the probability simplex to accommodate posterior shift. We derive a closed-form solution for the PDRO-ITR and develop an adaptive procedure to tune the uncertainty level. We establish risk bounds for the PDRO-ITR estimator, which guarantees robust performance under the worst case. Extensive simulations and two real-data applications demonstrate that the proposed method achieves superior performance compared to existing approaches.
format Preprint
id arxiv_https___arxiv_org_abs_2603_05568
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Learning Optimal Distributionally Robust Individualized Treatment Rules Integrating Multi-Source Data
Cui, Wenhai
Su, Wen
Zhao, Xingqiu
Machine Learning
Integrative analysis of multiple datasets for estimating optimal individualized treatment rules (ITRs) can enhance decision efficiency. A central challenge is posterior shift, wherein the conditional distribution of potential outcomes given covariates differs between source and target populations. We propose a prior information-based distributionally robust ITR (PDRO-ITR) that maximizes the worst-case policy value over a covariate-dependent distributional uncertainty set, ensuring robust performance under posterior shift. The uncertainty set is constructed as an individualized combination of source distributions, with weights combining prior source-membership probabilities and deviation terms constrained to the probability simplex to accommodate posterior shift. We derive a closed-form solution for the PDRO-ITR and develop an adaptive procedure to tune the uncertainty level. We establish risk bounds for the PDRO-ITR estimator, which guarantees robust performance under the worst case. Extensive simulations and two real-data applications demonstrate that the proposed method achieves superior performance compared to existing approaches.
title Learning Optimal Distributionally Robust Individualized Treatment Rules Integrating Multi-Source Data
topic Machine Learning
url https://arxiv.org/abs/2603.05568