Cost-optimal Sequential Testing via Doubly Robust Q-learning

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Zhou, Doudou, Zhang, Yiran, Jin, Dian, Zheng, Yingye, Tian, Lu, Cai, Tianxi
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866918446835433472
author Zhou, Doudou
Zhang, Yiran
Jin, Dian
Zheng, Yingye
Tian, Lu
Cai, Tianxi
author_facet Zhou, Doudou
Zhang, Yiran
Jin, Dian
Zheng, Yingye
Tian, Lu
Cai, Tianxi
contents Clinical decision-making often involves selecting tests that are costly, invasive, or time-consuming, motivating individualized, sequential strategies for what to measure and when to stop ascertaining. We study the problem of learning cost-optimal sequential decision policies from retrospective data, where test availability depends on prior results, inducing informative missingness. Under a sequential missing-at-random mechanism, we develop a doubly robust Q-learning framework for estimating optimal policies. The method introduces path-specific inverse probability weights that account for heterogeneous test trajectories and satisfy a normalization property conditional on the observed history. By combining these weights with auxiliary contrast models, we construct orthogonal pseudo-outcomes that enable unbiased policy learning when either the acquisition model or the contrast model is correctly specified. We establish oracle inequalities for the stage-wise contrast estimators, along with convergence rates, regret bounds, and misclassification rates for the learned policy. Simulations demonstrate improved cost-adjusted performance over weighted and complete-case baselines, and an application to a prostate cancer cohort study illustrates how the method reduces testing cost without compromising predictive accuracy.
format Preprint
id arxiv_https___arxiv_org_abs_2604_11165
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Cost-optimal Sequential Testing via Doubly Robust Q-learning
Zhou, Doudou
Zhang, Yiran
Jin, Dian
Zheng, Yingye
Tian, Lu
Cai, Tianxi
Machine Learning
Artificial Intelligence
Statistics Theory
Clinical decision-making often involves selecting tests that are costly, invasive, or time-consuming, motivating individualized, sequential strategies for what to measure and when to stop ascertaining. We study the problem of learning cost-optimal sequential decision policies from retrospective data, where test availability depends on prior results, inducing informative missingness. Under a sequential missing-at-random mechanism, we develop a doubly robust Q-learning framework for estimating optimal policies. The method introduces path-specific inverse probability weights that account for heterogeneous test trajectories and satisfy a normalization property conditional on the observed history. By combining these weights with auxiliary contrast models, we construct orthogonal pseudo-outcomes that enable unbiased policy learning when either the acquisition model or the contrast model is correctly specified. We establish oracle inequalities for the stage-wise contrast estimators, along with convergence rates, regret bounds, and misclassification rates for the learned policy. Simulations demonstrate improved cost-adjusted performance over weighted and complete-case baselines, and an application to a prostate cancer cohort study illustrates how the method reduces testing cost without compromising predictive accuracy.
title Cost-optimal Sequential Testing via Doubly Robust Q-learning
topic Machine Learning
Artificial Intelligence
Statistics Theory
url https://arxiv.org/abs/2604.11165