Monitoring Fidelity of Online Reinforcement Learning Algorithms in Clinical Trials
Anna L. Trella, Kelly W. Zhang, Inbal Nahum-Shani, Vivek Shetty, Iris Yan, Finale Doshi-Velez, Susan A. Murphy
TL;DR
Online RL in clinical trials offers targeted personalization but raises data-quality and participant-safety concerns. The authors define algorithm fidelity and present a two-phase framework—pre-trial planning and real-time monitoring—illustrated on Oralytics, which employs a generalized contextual bandit with Thompson sampling using per-step states $S_{i,t}$, actions $A_{i,t}$, and rewards $R_{i,t}$. The contributions include a formal fidelity concept, a concrete planning+monitoring framework with a red/yellow/green severity taxonomy, and actionable lessons from the Oralytics deployment since Spring 2023. The work provides practical guidance for safely translating rapid RL advances into real-world clinical trials while preserving the integrity of post-trial analyses.
Abstract
Online reinforcement learning (RL) algorithms offer great potential for personalizing treatment for participants in clinical trials. However, deploying an online, autonomous algorithm in the high-stakes healthcare setting makes quality control and data quality especially difficult to achieve. This paper proposes algorithm fidelity as a critical requirement for deploying online RL algorithms in clinical trials. It emphasizes the responsibility of the algorithm to (1) safeguard participants and (2) preserve the scientific utility of the data for post-trial analyses. We also present a framework for pre-deployment planning and real-time monitoring to help algorithm developers and clinical researchers ensure algorithm fidelity. To illustrate our framework's practical application, we present real-world examples from the Oralytics clinical trial. Since Spring 2023, this trial successfully deployed an autonomous, online RL algorithm to personalize behavioral interventions for participants at risk for dental disease.
