Implement CDISC CDASH-compliant CRF design in REDCap to streamline downstream SDTM mapping

Verified steps

1. Reference the CDISC CDASH Implementation Guide for the relevant domain (e.g., AE for adverse events, VS for vital signs, LB for laboratory tests) to identify the required, recommended, and permissible CDASH fields and their data types
2. Name REDCap fields using the CDASH variable name as the field name where possible (e.g., AESTDTC for adverse event start date, VSTESTCD for vital sign test code), adding the redcap_ prefix only for system-reserved names if needed
3. Assign controlled terminology to coded fields using NCI Thesaurus code lists (e.g., VSTEST for vital sign test names, AESEV for severity grades) as the answer choices in REDCap, storing the submission value (C-code or extensible term) as the raw code
4. For date and time fields, use REDCap's datetime field type with ISO 8601 format validation to ensure data is captured in SDTM-ready format (YYYY-MM-DD or YYYY-MM-DDThh:mm) without requiring post-export transformation
5. Document the CDASH-to-SDTM mapping for each CRF field in a mapping specification spreadsheet at the time of CRF design, specifying the SDTM domain, variable, controlled terminology version, and any derivation logic required
6. Validate the CRF design against the CDASH Implementation Guide annotated CRF template by creating an annotated PDF of the REDCap instrument showing the SDTM/CDASH variable name and origin for each field, which becomes part of the submission package