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Relationship concepts to link department to hospital?

The CDM for the CARE_SITE table states:

There can be hierarchical and business relationships between Care Sites. For example, wards can belong to clinics or departments, which can in turn belong to hospitals, which in turn can belong to hospital systems, which in turn can belong to HMOs.The relationships between Care Sites are defined in the FACT_RELATIONSHIP table.

However, when I look at the list of standard concepts in the Relations domain I only see concepts for person-to-person relations (e.g. ‘Brother’, ‘Child’). Could anybody recommend concepts to use to link departments to hospitals?


Where is this quotation from? We discussed this at length in Ohio back in the day and decided not to try to follow the organizational logic in the CDM for a number of reasons:

  • There is no use case
  • It is next to unintelligible from the outside
  • Even if it were possible to ascertain the structural relationship between the entities inside an organization is impossible to model. The administration has a different hierarchy than the physician organization has a different hierarchy than the specialty of the units has a different hierarchy than the geographical hierarchy has a different hierarchy than the commercial or legal entities.

Bottom line: It’s too hard, and has no value.



I use 46233688, ‘Care Site is part of Care Site’, and 46233689, ‘Care Site contains Care Site’. However, this doesn’t distinguish the physical relationships from the business relationships.

Hi @Christian_Reich. The quote is from the CDM GitHub pages.

If it is not used then that is fine, but in that case the documentation should be updated.

True. Will do.

The documentation still states the same. Does that mean that the statement in the documentation about departments and hospitals is true after all? And which relationship concept is the correct one then?

If not, what is the best way to handle ward movements during an inpatient visit? I thought about having the hospital as the care site of the visit occurrence and then in the visit_detail using the different wards as care sites. In the fact_relationship table, I would have mapped the different wards to the hospital. Or should I forget about the hospital and just use the first ward as care site for the visit occurrence?

Hello @HeideNei,


Your idea is correct and in alignment with the purpose of the Visit Occurrence and Visit Detail table definitions and conventions.

The following is also correct. It depends on your use case. Just be sure to document all decisions you make in conceptual logic (SQL is NOT documentation :slight_smile: )

If you chose option #1, then you won’t need the fact relationship table because you will link the children Visit Detail records to the parent Visit Occurrence record via the visit_detail.visit_occurrence_id

And before building out the hundreds or thousands of relationships between wards and hospitals in your fact relationship table, make sure you have a very strong use case for knowing this. We built out something similar years ago, as stated in my post above, and ended up not using it. Now we have additional columns (not OHDSI supported, not usable by Atlas or network research) on our Visit Occurrence and Visit Detail tables which support our in-house specific use case.