Bridging Probabilistic LLMs and Deterministic Statistical Validation: The PROVE Multi-Agent Framework for Clinical Trial Reporting

Ensuring the accuracy and consistency of clinical trial Tables, Figures, and Listings (TFLs) remains a major challenge in regulatory reporting. Independent programming and manual review are essential quality-control practices, but cross-output verification still depends heavily on reviewer inspection and may miss structural, logical, or arithmetic discrepancies. Large language models (LLMs) can help interpret varied table language and navigate lengthy study documents, but they are not reliable substitutes for programmed statistical checks. We introduce PROVE (Programmatic Reporting and Output Verification Engine), an auditable framework that uses optional LLM and retrieval support for table interpretation while reserving numerical and logical decisions for programmed validators. PROVE links findings to source evidence, supports cross-output consistency checks, and allows LLM use to be enabled or disabled based on study requirements. We evaluated PROVE using ten replicated synthetic oncology reporting packages generated from raw data through SDTM, ADaM, and TFL outputs, with paired clean and discrepancy-injected packages; each replicate included 15 randomly injected discrepancies. We examined two table-label settings: exact labels matching the validator vocabulary and labels with similar clinical meaning but different wording. Within the implemented rule classes, all automated PROVE variants achieved perfect classification in the exact-label setting. In the label-variation setting, LLM-assisted semantic matching improved overall recall from 0.588 to 0.993 and overall F1 from 0.735 to 0.996 compared with exact-match, fuzzy lexical, and embedding-similarity variants. These findings suggest that LLMs are most useful for interpreting real-world variation in TFL wording and formatting, while executable checks should remain responsible for final numerical validation.