Data Characteristics
Phase II-III clinical trial pre-screening data originates from clinical trial protocols, informed consent forms, case report forms (CRFs), medical imaging reports, laboratory test results, and historical medical records. These documents typically exist as PDFs, Word files, or in structured databases. Data updates are frequent during a trial, potentially daily or weekly, covering subject enrollment and visit data entry. Document structures are complex, containing extensive unstructured text descriptions (e.g., inclusion/exclusion criteria, adverse event records) and structured data (e.g., patient demographics, vital signs, lab indicators). Field units vary, such as blood pressure in mmHg, hemoglobin in g/dL, and tumor size in cm. Synonyms under different standards also exist.
Constraints on Citation and Traceability
The diversity and complexity of Phase II-III clinical trial data sources require a citation and traceability mechanism that accurately identifies different document types and data formats. Frequent data updates necessitate efficient incremental indexing and version management for the knowledge base, ensuring real-time accuracy of cited content. The mix of unstructured text and structured data challenges text segmentation and metadata extraction. The system must pinpoint citations to specific document paragraphs or structured fields. Variations in field units and the presence of synonyms can lead to ambiguity in model understanding and citation. Traceability must explicitly state original data units and context to prevent misinterpretation. Furthermore, citations of inclusion/exclusion criteria from trial protocols must precisely match the original text for compliance review.
Configuration Guidelines
| Configuration Item | Recommended Value | Rationale |
|---|---|---|
Chunk size (Segment Length) | 500–800 characters (characters) | Clinical trial documents have long paragraphs with multiple medical concepts; this length helps maintain contextual integrity. |
Recall count (Recall Count) | 10–15 entries (items) | Complex queries may involve multiple related factors; increasing recall improves coverage. |
Similarity threshold (Similarity Threshold) | 0.75–0.85 | Medical terminology requires high precision; a high threshold reduces irrelevant or ambiguous citations. |
Rerank result count (Rerank Return Count) | 5 entries (items) | After reranking, the top few items typically provide the most relevant direct evidence, reducing redundancy. |
Metadata Extraction Strategy | Structured Fields + Keywords | Combines structured data like patientID, visitDate with key unstructured descriptions for precise traceability. |
Citation Link Format | DocumentID-PageNumber-ParagraphID | Ensures citations link directly to the specific location in the original document for manual verification. |
Common Pitfalls
- Cited content fails to pinpoint the exact page or paragraph in the original document, making manual verification difficult. This happens when insufficient document hierarchy information is extracted and stored during knowledge base construction.
- AI responses cite outdated or revised trial data without indicating the data version or update date. This occurs due to inadequate configuration of version management and incremental update mechanisms for clinical trial data.
- The model confuses units or standards for different medical terms in its responses, for example, mistaking
mgforg. This happens when field unit information is not standardized or metadata-tagged during knowledge base construction.
Verification Steps
- Randomly select 10 pre-screening queries. Check if the document links cited in the AI responses accurately navigate to the corresponding page or paragraph in the original document.
- Choose 5 recently updated clinical trial documents. Verify if the citations in the knowledge base reflect the latest version of the data.
- For queries involving critical inclusion/exclusion criteria, compare the cited conditions in the AI response with the exact wording, including units and numerical ranges, from the original trial protocol.
The values given are common starting points and should be measured against the reader's own samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-21.