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Cohort and cohort definition tables filled during the mapping process

Implementers
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#1

Hi all,

I have a question regarding the mapping of our ongoing registry study data to the CDM. During my review, I noticed that the “cohort” and “cohort_definition” tables are being populated with study-specific data, including a theoretical end date for the study in the “COHORT_END_DATE” field.

This approach has led to two plausibility failures in the Data Quality Dashboard. While I understand the rationale of using a projected end date since the study is still ongoing, I would like to understand:

  1. Is it best practice to include study-specific information in the “cohort” and “cohort_definition” tables? Could this impact the intended use of these tables or potentially cause issues with tools like Atlas?
  2. What are the implications of using a projected end date instead of the actual end date, especially regarding data quality checks and analysis?

Thank you!

#2

I’m not sure what ‘study specific information’ is, but I can tell you that Atlas does not use the cohort tables found in the CDM schema. The history of this decision is that the cdm schema is typically read-only while the results schema is not (we write our analytical results there). Also, we needed freedom to modify the results schema between releases of Atlas, while the CDM schema follows its own release cadence.

-Chris

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#3

Thank you so much for your reply! It’s very helpfull.

Best,

#4

Hi @Chris_Knoll Can you tell me which table has the cohort names I can see on the Cohort Definitions screen in Atlas? I tried looking for them in the cohort_inclusion table in the cdm_results schema, but the names are not the ones I can see on the screen…
Thank you,
Alla

#5

The cohort names are part of the definition which is in the webapi’s cohort_definition table.

#6

Thank you.

#7

Hi again,

I hope this message finds you well. I’m reaching out again for some clarification on using the cohort tables in the CDM.

We are storing the following study-specific information in the cohort table within the CDM schema and not the result schema:

  • Study Start Date: This is represented as the date of each participant’s first enrollment in the study.
  • Study End Date: This is the projected end date of the entire study.

My main question is about how Atlas would interact with this information :

  • Can Atlas directly access and analyze these study start and projected end dates if they are stored within the cohort and cohort_definition tables in the CDM schema?

Thank you so much for your patience and help in understanding this!

Best,

#8

No, Atlas does not use any information in the cohort definition table in the cdm schema.

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