We are using the Cohort table to identify cohorts derived from our source + OMOP data. We will mostly be using these data for feasibility studies. Of the persons with Condition X how many are part of Cohort Y?
The Cohort table does not have a primary key. Shouldn’t the table have a PK? The Cohort Definition table has a PK, as do the clinical event tables and the derived tables.
Also, from the conventions I found this blurb which doesn’t make sense “A subject can only have one record in the cohort table for any moment of time, i.e. it is not possible for a person to contain multiple records indicating cohort membership that are overlapping in time”. A person can have overlapping cohort records when they are a member of more than one cohort. Does the conventions statement need to be reworded? Or am I misinterpreting it?