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Drug Group Era under Characterization tool

(Shinyoung Ju) #1

Hi OHDSI enthusiasts,

I had a quick question regarding Drug Group Era features in Characterizaion tool.
I used this function to view the list of medications used by a cohort before the index dates (30 days, 180 days, and 365 days) which are groupped by ATC 1 through 4 levels.
However, I see all ATC levels in one single list, and found it difficult to interpret why some medications are groupped with ATC level 4 whereas the other medications are groupped with ATC leve 1. In order to make the list more harmonized, I wanted to know if there is a way for me to choose a specific ATC level.

It owuld be GREATLY appreciated if any of you could give me some insight on this – (maybe I do not fully understnad ATC grouppings?) We can have a call as well. Please let me know :wink:

Best regards,

(Seng Chan You) #2

You can find how it works here
It seems like feature extraction package of OHDSI tool ecosystem classifies drug according to ATC group level 1, 3, 4, and 5. And I think they’re overlapped. You can make your own custom feature extraction function based on the code above.

Could you add some more comments? @schuemie

(Martijn Schuemie) #3

The drugs are simply rolled up the ATC hierarchy provided by the Vocabulary. A single drug will therefore be represented at multiple ATC levels.

I don’t know if there’s a way to limit your features to a specific ATC level in the Characterization tool. If you’re running FeatureExtraction in R you could write some SQL to select only those characteristics corresponding to a specific level.