ClinicalTrials Study Detail¶
Retrieves detailed information for a single clinical study from ClinicalTrials.gov using its NCT ID. Supports JSON or CSV output and allows selecting specific fields and markup formatting for rich-text fields.
Usage¶
Use this node when you need the full record for a specific trial after you have an NCT ID (e.g., from a search step) or when you already know the study identifier. Typically placed after a study search or list node to fetch full details for a chosen study and then route the result to parsing, analysis, or display steps.
Inputs¶
| Field | Required | Type | Description | Example |
|---|---|---|---|---|
| nct_id | True | STRING | The ClinicalTrials.gov NCT identifier of the study to retrieve. | NCT04000165 |
| format | True | STRING | Response format. Choose 'json' for structured JSON, or 'csv' for a CSV text response. | json |
| markupFormat | True | STRING | Markup format for any rich-text fields returned by the API. 'markdown' or 'legacy'. | markdown |
| fields | False | STRING | Optional comma-separated list of fields to include in the response. Leaving empty returns the default set. | BriefTitle, OverallStatus, Conditions, EnrollmentCount |
Outputs¶
| Field | Type | Description | Example |
|---|---|---|---|
| results | STRING | The study details returned by the ClinicalTrials.gov API. JSON string when format='json'; CSV text when format='csv'. | { "apiVersion": "2.0", "studies": [ { "protocolSection": { "identificationModule": { "nctId": "NCT04000165", "briefTitle": "..." } } } ] } |
| metadata | STRING | Metadata about the response, including the NCT ID and format. For JSON responses, may include the API version; for CSV, includes content length. | { "nct_id": "NCT04000165", "format": "json", "api_version": "2.0" } |
Important Notes¶
- Endpoint behavior: Queries ClinicalTrials.gov API v2 at /studies/{nct_id}.
- Output types: Results are always returned as strings. JSON format returns a JSON string; CSV returns raw CSV text.
- Field selection: Use the 'fields' parameter to limit payload size and focus on specific attributes.
- Markup control: 'markupFormat' applies to rich-text fields; choose 'markdown' for modern formatting or 'legacy' for older style.
- Error handling: On network/decoding errors, the node returns simple JSON error strings in both outputs rather than raising exceptions.
- NCT ID validity: An invalid or non-existent NCT ID may return an error from the API or an empty payload.
- Rate limits/latency: External API calls may be rate-limited or slow; plan for retries or backoff upstream if needed.
Troubleshooting¶
- Empty or unexpected results: Verify the NCT ID is correct and active. If using 'fields', ensure the field names are valid; try removing 'fields' to compare.
- CSV parsing issues: If format='csv', downstream steps must parse CSV text. Switch to 'json' for structured parsing.
- Markup rendering problems: If rich-text fields display oddly, switch 'markupFormat' between 'markdown' and 'legacy' to match your renderer.
- Network errors or timeouts: Check connectivity and try again. The node returns an error JSON string; implement retry logic upstream if necessary.
- Large responses: If the output is too large to handle, restrict 'fields' to only what you need.
- Invalid fields parameter: If specific fields are not recognized by the API, they may be ignored or cause minimal data; validate field names against ClinicalTrials.gov documentation.