Causal-Enhanced AI Agents for Medical Research Screening
Duc Ngo, Arya Rahgoza
TL;DR
The paper tackles the infeasibility and trust challenges of automated medical evidence synthesis by fusing causal graph reasoning with retrieval-augmented generation. It introduces CEAI, a framework that enforces evidence-first causal relationships grounded in retrieved literature using LightRAG's dual-level retrieval and a Think tool to construct explicit DAGs. The authors demonstrate, on a dementia-exercise corpus of 234 abstracts, that a causal graph–enhanced agent (CausalAgent) achieves 95% accuracy, 100% retrieval success, and zero hallucinations, outperforming baseline and lightweight retrieval systems. The work presents a blueprint for trustworthy, interpretable medical AI that supports high-stakes decision-making and explains mechanisms via causal graphs, with open implementation and clear directions for broader validation. Overall, the approach shows transferable principles for integrating causal reasoning into AI-assisted evidence synthesis in healthcare, improving reliability, interpretability, and clinical utility.
Abstract
Systematic reviews are essential for evidence-based medicine, but reviewing 1.5 million+ annual publications manually is infeasible. Current AI approaches suffer from hallucinations in systematic review tasks, with studies reporting rates ranging from 28--40% for earlier models to 2--15% for modern implementations which is unacceptable when errors impact patient care. We present a causal graph-enhanced retrieval-augmented generation system integrating explicit causal reasoning with dual-level knowledge graphs. Our approach enforces evidence-first protocols where every causal claim traces to retrieved literature and automatically generates directed acyclic graphs visualizing intervention-outcome pathways. Evaluation on 234 dementia exercise abstracts shows CausalAgent achieves 95% accuracy, 100% retrieval success, and zero hallucinations versus 34% accuracy and 10% hallucinations for baseline AI. Automatic causal graphs enable explicit mechanism modeling, visual synthesis, and enhanced interpretability. While this proof-of-concept evaluation used ten questions focused on dementia exercise research, the architectural approach demonstrates transferable principles for trustworthy medical AI and causal reasoning's potential for high-stakes healthcare.
