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Differences between ddls vs CDM pdf


I’m working on a conversion using the 5.2 version of the common data model. I’m using the ddls defined in the github repository to setup the schema (for example postgres dll → CommonDataModel/OMOP CDM ddl - PostgreSQL.sql at v5.2.0 · OHDSI/CommonDataModel · GitHub)

However, if I look to the OMOP Common Data Model v5.2 Specifications pdf there are some differences between the ddls schema and the information on document.

This looks to happen for the datetime fields like for example procedure_datetime, observation_period_start_datetime, observation_period_end_datetime, drug_exposure_start_datetime, condition_start_datetime for both 5.2.0 and 5.2.2 CDM versions where they are all not null/required in the ddls but in the pdf document they are described as required.

My question is what should I consider as the valid CDM? The one in the ddls or the one in the pdf document?

Many thanks,

The documentation is correct, date time columns should be Nullable. Date vs DateTime columns have been a topic of conversation. Do you have a use case where DateTime is important for any or your analyses?

Thanks for the reply @DTorok. No, I’m not using the DateTime fields, but I was wondering what was the correct definition of the CDM to build conversions that match what is accepted by the community. I will use the schema defined in the documentation and not make dateTime fields required.