Development and evaluation of an agentic LLM based RAG framework for evidence-based patient education

Objectives To develop and evaluate an agentic retrieval augmented generation (ARAG) framework using open-source large language models (LLMs) for generating evidence-based Arabic patient education materials (PEMs) and assess the LLMs capabilities as validation agents tasked with blocking harmful content. Methods We selected 12 LLMs and applied four experimental setups (base, base+prompt engineering, ARAG, and ARAG+prompt engineering). PEM generation quality was assessed via two-stage evaluation (automated LLM, then expert review) using 5 metrics (accuracy, readability, comprehensiveness, appropriateness and safety) against ground truth. Validation agent (VA) performance was evaluated separately using a harmful/safe PEM dataset, measuring blocking accuracy. Results ARAG-enabled setups yielded the best generation performance for 10/12 LLMs. Arabic-focused models occupied the top 9 ranks. Expert evaluation ranking mirrored the automated ranking. AceGPT-v2-32B with ARAG and prompt engineering (setup 4) was confirmed highest-performing. VA accuracy correlated strongly with model size; only models ≥27B parameters achieved >0.80 accuracy. Fanar-7B performed well in generation but poorly as a VA. Discussion Arabic-centred models demonstrated advantages for the Arabic PEM generation task. ARAG enhanced generation quality, although context limits impacted large-context models. The validation task highlighted model size as critical for reliable performance. Conclusion ARAG noticeably improves Arabic PEM generation, particularly with Arabic-centred models like AceGPT-v2-32B. Larger models appear necessary for reliable harmful content validation. Automated evaluation showed potential for ranking systems, aligning with expert judgement for top performers.