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Classifying surgical complications


(Andreas Weinberger Rosen) #1

Dear all,

I’m currently mapping data for patients who underwent colorectal surgery. Our complications are classified by a widely used system called Clavien Dindo, which I unfortunally can’t find as a concept on Athena. Would any of you have implemented surgical complications in your CDM with the Clavien Dindo classification, and what was your approach for it?


Andreas Rosen

(Anna Ostropolets) #2

Yes, there is a classification that uses Clavien grades to specify the severity of complications. I don’t know any official terminology that contains it though.
What can be done: you can create custom concepts with 2bil+ concept_ids to represent those grades,e.g. Clavien Grade I etc., and link them to your actual complications through fact_relationship or create separate concepts for each complication (e.g. Pneumonia CG I, Pneumonia CG II etc). The first approach seems to be less messy.

(Christian Reich) #3


That’s a good question. In general, observational data contain the sheer primary facts. Those classifications or scores are usually derived, or “abstracted”. So, in your case you would create an algorithm for deriving e.g. a Clavien-Dindo Grade III Classification by creating a patient population with a surgery, and a subsequent “surgical, endoscopic or radiological intervention”. Currently, such algorithms would result in membership of a Cohort (records in the COHORT table). Alternatively, you could do what @aostropolets suggests and create your own internal vocabulary, but that will not be interoperable with the rest of the Network.

However, we know that there are data sources which contain the abstracted information. This, and the desire to create standardized OHDSI-wide algorithms we are working on a proposal for an EPISODE table. This is particularly important for cancer research.

Do you have Clavien-Dindo data, or are you working on the algorithm?

(Andreas Weinberger Rosen) #4

Dear Christian and Anna,

Thank for both your input. In the registry we’re currently mapping we unfortunately only have detailed data on their primary surgery, we only have the different complications with a Clavien Dindo grade, so even tough the creation of the algorithmn would be a very elegant solution, I wouldn’t be able to create it form this source alone.

I think your solution Anna is a great way to solve this for now.



(Christian Reich) #5

@awrosen: Nothing wrong with Anna’s proposal, of course, but just keep in mind: Once we have the Episode table that’s where these things should live, NO MATTER if they are abstracted from the raw data or you are getting them directly.

Anna’s proposal has two disadvantages: First, as I said before, it is not interoperable, and second, you will have a hard time defining the domains. And even when you define the domains they will be different, resulting in your scores in different tables: Conditions (e.g. “multi organ dysfunction”, Observations (e.g. “any deviation from the normal postoperative course”), Drugs (e.g. “antiemetics, antipyretics, analgetics, diuretics and electrolytes”) or Procedures (e.g. “surgical, endoscopic or radiological intervention”). You could make them all Observations and call them “Grade I Clavien-Dindo Score” etc., but then you would miss the fact that these indicate clinical events. Ugly one way or another.

(Anna Ostropolets) #6

Clavien Grades will be observations, so no need to mess with domains. Then, as proposed, you can link them to the actual events through fact_relationship, so that they will be linked. Should work as a temporary solution. As a permanent one, these grades should be added to a vocabulary (which one?).

(Dmytry Dymshyts) #7

NCI vocabulary has these Clavien-Dindo Scores.
NCI is not OMOPed. And it will never be due to messy structure and lack of relationships to other vocabularies, right, @Christian_Reich?

(Christian Reich) #8

Well, there are like 7 or so scores. We wouldn’t need NCI if we just wanted to add those.