MED-COPILOT: A Medical Assistant Powered by GraphRAG and Similar Patient Case Retrieval

TL;DR

MED-COPILOT is an interactive clinical decision-support system that combines structured guideline knowledge with patient case retrieval to improve reasoning accuracy and transparency in medical AI applications.

Contribution

It introduces a novel system integrating guideline-grounded GraphRAG retrieval with similar patient case retrieval, enhancing clinical reasoning and evidence transparency.

Findings

Outperforms baseline LLMs and RAG in clinical note completion

Improves medical question answering accuracy

Enhances interpretability with evidence inspection tools

Abstract

Clinical decision-making requires synthesizing heterogeneous evidence, including patient histories, clinical guidelines, and trajectories of comparable cases. While large language models (LLMs) offer strong reasoning capabilities, they remain prone to hallucinations and struggle to integrate long, structured medical documents. We present MED-COPILOT, an interactive clinical decision-support system designed for clinicians and medical trainees, which combines guideline-grounded GraphRAG retrieval with hybrid semantic-keyword similar-patient retrieval to support transparent and evidence-aware clinical reasoning. The system builds a structured knowledge graph from WHO and NICE guidelines, applies community-level summarization for efficient retrieval, and maintains a 36,000-case similar-patient database derived from SOAP-normalized MIMIC-IV notes and Synthea-generated records. We evaluate our framework on clinical note completion and medical question answering, and demonstrate that it consistently outperforms parametric LLM baselines and standard RAG, improving both generation fidelity and clinical reasoning accuracy. The full system is available at https://huggingface.co/spaces/Cryo3978/Med_GraphRAG , enabling users to inspect retrieved evidence, visualize token-level similarity contributions, and conduct guided follow-up analysis. Our results demonstrate a practical and interpretable approach to integrating structured guideline knowledge with patient-level analogical evidence for clinical LLMs.