基于决策基础的合同用于可审计的LLM辅助医疗账单审核：确定性规则、逐字证据与故障关闭式弃权
A decision-basis contract for auditable LLM-assisted medical billing verification: deterministic rules, verbatim evidence, and fail-closed abstention
- Aschaffenburg University of Applied Sciences（阿沙芬堡应用科学大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究提出一种基于决策基础合同的LLM辅助医疗账单审核方法，通过分离确定性规则与语义评估，要求逐字证据并采用故障关闭式弃权，实现可审计的决策记录，实验显示明确文档要求提升缺失信息识别。
AI中文摘要：
本工作提出了一种基于决策基础合同的可审计LLM辅助医疗账单审核的概念验证。该合同将版本化费用目录规则的确定性检查与基于LLM的自由文本文档评估分离开来。确定性层解析适用的目录版本，并检查代码可用性、数量限制和排除项。语义层将每个索赔项目分类为支持、矛盾或缺少所需信息。支持和矛盾需要逐字证据片段；不可用的规则上下文、不成功的评估或缺少所需证据会通过故障关闭式弃权（不执行）阻止支持。我们在合成目录和36个精选案例上评估了四个本地运行的开权重模型，采用该合同、无明确文档要求的消融以及端到端基线。结果一致性因模型而异，且相对于基线无一致优势。明确文档要求提高了所有四个模型对缺失信息的识别能力。证据门控还暴露了正确原始判断缺乏有效证据并转换为不完整决策基础条目的情况。结果表明，明确的决策记录可使规则发现、文档判断和弃权原因可检查。需在真实目录、独立标注文档及人工评审者参与下进行评估，以确定实际价值。
英文摘要：
This work presents a proof of concept for auditable LLM-assisted medical billing verification based on a decision-basis contract. The contract separates deterministic checks of versioned fee-catalog rules from LLM-based assessment of free-text documentation. The deterministic layer resolves the applicable catalog release and checks code availability, quantity limits, and exclusions. The semantic layer classifies each claimed item as supported, contradicted, or missing required information. Support and contradiction require a verbatim evidence span; unavailable rule context, unsuccessful assessment, or missing required evidence prevents support through fail-closed abstention. We evaluated four locally run open-weight models on a synthetic catalog and 36 curated cases under the contract, an ablation without explicit documentation requirements, and an end-to-end baseline. Outcome agreement varied across models and showed no consistent advantage over the baseline. Explicit documentation requirements improved identification of missing information for all four models. The evidence gate also exposed cases in which correct raw judgments lacked valid evidence and were converted to incomplete decision-basis entries. The results show how explicit decision records can make rule findings, documentation judgments, and abstention reasons inspectable. Evaluation on real catalogs, independently annotated documentation, and with human reviewers is required to assess practical value.
