ANCHOR (Auditable Navigation of Clinical Hazards With Oversight and Reasoning) Multicenter Randomized Validation Study: A Pragmatic Three-Arm (1:1:1) Patient-Level Randomized Controlled Trial of a Structural Verification Layer for AI-Assisted High-Risk Multidisciplinary Care Across Three U.S. States

Summary

This pre-registered, pragmatic, three-arm (1:1:1) patient-level randomized controlled trial with mixed-effects analysis at the encounter level tests two questions in real high-risk multidisciplinary clinical encounters at the Waymark clinically integrated network across three U.S. states (Ohio, Washington, Virginia): (1) does adding ANCHOR - a clinical AI structural verification layer - to a Gemini 3.1 Pro-assisted supervising-physician workflow reduce the rate of clinically meaningful safety failures, compared with the same Gemini 3.1 Pro-assisted workflow without ANCHOR? (2) does the Gemini 3.1 Pro-assisted workflow itself reduce the same safety endpoint compared with unassisted standard care in which the supervising physician writes their own SOAP assessment/plan from a blank template? ANCHOR is a single-call structural verification layer combining a Logical Neural Network (Riegel et al. 2020) certificate, six specialist agents, and concept-decomposed output with PMID citation provenance. ANCHOR is physician-facing only and is used by supervising physicians, not by the multidisciplinary clinical team they oversee. The trial randomizes 240 patients 1:1:1 across the Waymark clinically integrated network over a 12-week active-enrolment window (80 per arm). Eligible patients are adults (age 18+) identified as high-risk by combined claims-based and clinical criteria. Eligible encounters span three integrated Waymark service modalities: high-risk primary care, specialty care coordination, and real-time telemedicine urgent care. The primary endpoint is a per-encounter binary composite: any of (a) failure to mention a do-not-miss diagnosis, (b) under-triage, (c) contraindicated medication recommendation, (d) failure to recommend escalation when clinically warranted; adjudicated by a blinded panel of 3 board-certified physicians with majority-of-three scoring. The primary contrast is Arm 3 (LLM+ANCHOR) versus Arm 2 (LLM with safety prompt), isolating ANCHOR's marginal contribution over a deployment-equivalent LLM safety stack. The pre-specified secondary contrast is Arm 2 versus Arm 1. The trial is sized to the operational ceiling of the Waymark integrated-network workflow across the three states (240 enrollees over 12 weeks). At realistic effect sizes derived from the retrospective evaluation, the trial is underpowered for definitive efficacy declaration on either pairwise contrast and is reported as an initial deployment-feasibility validation cohort with effect estimates and 95 percent confidence intervals; full power calculations are pre-registered in the Statistical Analysis Plan. Single-blind outcome adjudication: 3 adjudicators score only the supervising physician's final clinical decision, so all three arms produce adjudication packets in identical format and arm allocation is structurally invisible. Statisticians remain blinded until database lock. A full waiver of informed consent is requested per 45 CFR 46.116(f)(3) with a companion HIPAA waiver of authorization under 45 CFR 164.512(i)(2)(ii). The study is registered on the Open Science Framework prior to first enrollment and reported under CONSORT-AI 2020.