I’m starting to learn the basics of OMOP, Atlas… and I have some simple questions.
What is the difference between cohort and era?
The book of OHDSI defines…
COHORT as a set of persons who satisfy one or more inclusion criteria for a duration of time. (Often interchanged with the term phenotype).
A CONDITION ERA is defined as a span of time when the Person is assumed to have a given condition.
I find both definitions quite similar.
Is it just that cohort refers to the persons and era is the time?
I’m also confused between “cohort entry events” and “inclusion criteria” in ATLAS. May they be interchangeable?
For example if I want to predict or estimate death among people who (take aspirin & have had a stroke).
I could use…
the date of the first aspirin intake as cohort entry and the date of stroke as inclusion criteria.
or reverse the order and use…
stroke as cohort entry and aspirin intake as inclusion criteria.
Would it be the same?
Everything could be considered both as an event and as a inclusion criteria?
There is a tutorial where “ace inhibitors” is used as cohort entry event and “diagnosis hipertension” as inclusion criteria. Why not the opposite?