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Nested criteria interpretation

Hi all,

Could someone explain how the nested criteria is applied in Atlas?

Here is an example of Arni use and a nested criteria with Beta blocker use (subgroup section within Characterization in Atlas).

which one is true?

  1. system just goes from the outside to the inside and applies the defined criteria - that would mean that although ARNi drug era would only start after the index date, since I provided the criteria for Beta blocker: drug era starts all days before Arni start date, beta blocker start date may be prior to the main index date.

  2. the outside criteria applies to the nested criteria as well. so in this case even if i provide the criteria for beta blockers drug era start date: áll days before Arni start date, beta blocker start date won´t be earlier than the main index start date (since I provided the criteria for ARNi: event starts 0 days before index start date).

This is very crucial to understand, I hope somone can enlighten me.

Thank you very much!

It is closer to 1. When you use nested criteria, all context about the outer index date (which in this case is your cohort entry criteria because you are showing an inclusion rule here), and when you move into nesting, your criteria that you are nesting to becomes the new index (which is why in the nested criteria you get the message that 'the index date refers to the ARN drug era).

The reason why i say it is closer to 1 is that you say that the Beta blocker drug erra starts all days before arni, but you said the beta could also start any time after index (the ARNI), so what you are really saying is that you want to find ARNI drug eras that started on or after your cohort entry, but only if the person also has a beta blocker era that lasted at least 30 days. I say ‘the person also has’ because you’ve not given any time boundry to the ARNI era, so it’s basically saying any time, aka: the person also has the beta blocker.