Objective: To allow adequate representation of clinical trial data in OMOP.

First use case: To convert clinical trial data in CDISC SDTM format to OMOP, with a view to allowing trial planning optimization.

Approach: We advocate minimum changes to the OMOP CDM and Standardized Vocabularies because we want to ensure minimum impact on OHDSI tools like Atlas, whilst providing a value-add SDTM-to-OMOP conversion with minimum data loss. We have proposed conventions introducing new concepts and modifiers, but no new CDM tables; and providing guidance for ETL developers where appropriate. Our proposals were originally built on OMOP CDM v6 and the Oncology extension, with v5.3 backward compatibility. In a new v5.4 the additions from the Oncology extension became standard, which made our changes minimal, thereby, making our proposals fully compatible with v5.4.

Status:
- 2025: CTWG is providing new chapter content (Clinical Trial Data) for the upcoming Book of OHDSI update. - 2024: The finalization of C-Path SDTM-to-OMOP mappings is underway, with an emphasis on matching concept codes using Usagi. The next step is to execute ETL queries to generate the OMOP CDM tables. Additionally, a secondary objective is to identify general conventions and best practices for clinical trials. These conventions will be applied to additional C-Path SDTM study data to uncover any further gaps or challenges.
- 2023: The team has transitioned from using Vivli (due to access constraints) data to leveraging SDTM data provided by C-Path for tuberculosis. The development of mapping specifications for the subsequent ETL process will proceed from the initial stages.
- 2022: CTWG has been granted access to 20 Vivli clinical study packages in SDTM format. The team is conducting an inventory of these study packages to prioritize SDTM-to-OMOP mappings. The current CTWG guidance topics will be further evaluated, with new topics identified as needed.
- 2021: CTWG conducted an assessment of clinical trial data providers to identify sources of accessible SDTM data. This assessment led to discussions with Vivli, focusing on general data usage agreements and evaluating the feasibility of their platform.
- 2020: Used a synthetic representation of the CDISC SDTM data via PHUSE Test Data. Initial guidance topics were codified but require further testing with diverse real world SDTM data. The CTWG proposals submitted to the OHDSI community in July 2020.