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Atlas - Adding date range logic

Hello -

I am trying to create a new cohort definition that has multiple criteria with specific date range logic. I have noticed that the date range in each additional criteria will refer to the initial event’s start date, called the ‘index start date’. The index start date can toggle to an ‘index end date’ option, which refers to the initial event’s end date.

However, is there a way to set the index start date to refer to another criteria’s start date? In other words, is there a way to add criteria with a date range that refers to another criteria instead of the initial event?

For example, is it possible to apply the following logic?

  • initial event - a procedure occurrence
  • additional criteria 1 - a condition diagnosis 10 days after the initial event
  • additional criteria 2 - a drug exposure 10 days after the condition diagnosis

Thank you.

You can do this by using nested criteria. That’s the only way to reference a new index date other than the initial event. There is not a way that you can refer to an index date to some other arbitrary external criteria. With nested criteria, you ‘re-establish’ an index and apply criteria to it.

Thanks @Chris_Knoll. Could you please explain how to insert nested criteria? Or point me to documentation that explains nesting?

Within a criteia, you can add a ‘nested criteria’. It is one of the options in the dropdown (such as start date, end date,you get to the options through the ‘add attribute’ button in the top right (nested criteria is one of the attributes you can add).

There is a set of tutorials in Ehden Academy: https://academy.ehden.eu/course/view.php?id=9.

You can create an account and go to the Phenotype Definition, Characterisation and Evaluation course, and watch the videos.