OHDSI Clinical Trials Working Group

Overview

The OHDSI Clinical Trials Working Group (CTWG) is an active working group within OHDSI developing conventions and guidance for converting clinical trial data in CDISC SDTM format into the OMOP CDM. Its goal is to enable trial data to be analysed alongside real-world observational data using the OHDSI toolset, supporting trial planning optimisation and cross-study comparisons.

The working group advocates minimal changes to the OMOP CDM to ensure compatibility with OHDSI tools such as ATLAS. Its proposals — built on OMOP CDM v5.3 — became largely incorporated into OMOP CDM v5.4 via the Oncology extension. As of 2025, the CTWG is writing a new Clinical Trial Data chapter for the Book of OHDSI.

Status

SDTM-to-OMOP conversion remains uncommon in practice. The working group’s output should be understood as community guidance and feasibility work rather than a mature, standardised ETL pipeline in widespread use.

Connections

• Part of: OHDSI
• Interoperability work: CDISC (SDTM) ↔ OMOP CDM

Resources

• https://www.ohdsi.org/web/wiki/doku.php?id=projects:workgroups:clinicalstudy (CTWG wiki page)
• https://github.com/OHDSI/CommonDataModel/issues/358 (original CDM proposal)