Patient-safety reasoning without the knowledge graph loses 0.047 F1, while retrieval's gain straddles zero
Patient-safety reasoning requires linking clinical narratives, medications, laboratory findings and adverse events, and a language model alone can produce plausible but unsupported conclusions. The same MIMIC-III/IV cases ran under four conditions with one LLaMA 2 7B model and one prompt: model only, plus retrieval-augmented generation, plus a patient-safety knowledge graph and ontology, and both. The full framework reached F1 0.89 for concept extraction, 0.046 above baseline; removing the knowledge graph cost the most, with F1 0.047, AUROC 0.084 and AUPRC 0.110, while removing retrieval gave an F1 difference of 0.029 whose interval crossed zero.