FHIR-AgentBench: Benchmarking LLM Agents for Realistic Interoperable EHR Question Answering
Existing benchmarks inadequately assess large language model (LLM) agents’ capabilities on real-world, HL7 FHIR-standardized clinical data. Method: We introduce FHIR-AgentBench—the first realistic clinical question-answering benchmark grounded in FHIR, comprising 2,931 clinically grounded questions derived from authentic electronic health record (EHR) scenarios. For the first time, we systematically evaluate LLM agents within the FHIR resource model framework, comparing strategies including API-based vs. domain-specific tool usage, single-turn vs. multi-turn interaction, and natural-language vs. code-based generation—thereby uncovering core challenges: retrieval ambiguity, cross-resource relational modeling, and multi-step clinical reasoning. Contribution/Results: We publicly release an open-source dataset and evaluation suite. Empirical analysis identifies critical performance bottlenecks of current agent approaches on structured clinical queries, advancing reproducible, interoperable research on clinical AI agents.