ClinicalTrials Study Count¶
Retrieves a count of clinical studies from ClinicalTrials.gov that match a given condition or disease. Returns the result content and a metadata summary, supporting JSON or CSV output formats with basic error handling for network and parsing issues.
Usage¶
Use this node when you need the number of studies that match a search term on ClinicalTrials.gov, optionally limiting returned fields. Typical workflow: provide a condition or disease query, choose output format (JSON recommended), optionally specify fields, then feed the count/metadata to subsequent filtering, reporting, or visualization steps.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| condition_or_disease | True | STRING | Primary search query for the condition, disease, or term to match studies on ClinicalTrials.gov. | diabetes |
| format | True | STRING | Response format for the results content. Supported values: json, csv. JSON provides structured data including totalStudies; CSV returns raw text content. | json |
| fields | False | STRING | Comma-separated list of fields to include in the response. Leave empty to use API defaults. | NCTId,BriefTitle,OverallStatus |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| results | STRING | The response content. For format=json, a JSON string including the API response and a totalStudies summary; for format=csv, the raw CSV text. | { "data": { ... }, "query": "diabetes", "total_studies": 1234, "min_rank": 1, "max_rank": 10, "api_version": "2.0" } |
| metadata | STRING | Metadata about the request/response. For JSON: includes query, format, and api_version. For CSV: includes query, format, and content_length. | { "query": "diabetes", "format": "json", "api_version": "2.0" } |
Important Notes¶
- The node queries the ClinicalTrials.gov API v2 using a condition/disease search and summarizes counts based on the API response.
- Supported formats are json and csv; xml is not supported by this node.
- When format=json, the node returns a JSON string with totalStudies and other summary fields; when format=csv, it returns raw CSV text.
- If no studies match the query, totalStudies may be 0 and the results content may be minimal.
- Network timeouts and errors are handled by returning an error JSON string in both outputs.
Troubleshooting¶
- Network error: Ensure internet connectivity and that ClinicalTrials.gov API is reachable. The node returns an error string like {"error": "Network error"}. Retry later or adjust timeout upstream if applicable.
- JSON decode error: If format=json and the API returns non-JSON content, you will receive {"error": "JSON decode error"}. Switch to CSV or try again later.
- Empty or unexpected results: Verify the condition_or_disease query string and try simplifying it. Check that fields are valid API fields when provided.
- CSV output looks truncated: Check the metadata output's content_length to confirm size. Long outputs may need downstream handling for display or storage.