How to query location resource hierarchy?

[liamwilson-kainos]

Hi all,

I am using version 4 of the FHIR standards and as an example I have a location hierarchy of referenced resources. Given the example below -

Location 1 - 006b7615-7f41-47af-af1d-c4299924f224 is a hospital
Location 2 - 0737f820-768d-4386-83a6-e3d6af2cb2d3 is a ward
Location 3 - 07238beb-e53d-4225-9320-9f8b6668864f is a room

These are connected through the partOf reference - https://hl7.org/fhir/R4/location-definitions.html#Location.partOf.

Is it possible to query using the ID of the hospital 006b7615-7f41-47af-af1d-c4299924f224 and then find all referenced resources down the chain?

I have experimented with the following and seem to only get one layer of references and I cant go beyond one level.

https://{host}/Location?_revinclude:iterate=Location:partof&_id=006b7615-7f41-47af-af1d-c4299924f224

https://{host}/Location?_revinclude:recurse=Location:partof&_id=006b7615-7f41-47af-af1d-c4299924f224

https://{host}/Location?_revinclude=Location:partof&_id=006b7615-7f41-47af-af1d-c4299924f224

https://{host}/Location?_include=Location:partof&_id=006b7615-7f41-47af-af1d-c4299924f224

https://{host}/Location?_include=Location:partof&_id=006b7615-7f41-47af-af1d-c4299924f224

https://{host}/Location?_include=Location:partof&_id=006b7615-7f41-47af-af1d-c4299924f224

I have seen the following warning and came across #2137.

"issue": [
    {
        "severity": "information",
        "code": "informational",
        "diagnostics": "The parameter _revinclude:iterate=Location:partof with circular reference is executed once (a single iteration)."
    }
]

Any advise please?

Thanks!

[liamwilson-kainos]

My colleague managed to figure out what we needed - for anyone else having a similar issue

Starting at the top of the tree (Location 1 from my example)

https://{host}/Location?_revinclude=Location:partof&_revinclude:iterate=Location:partof&_id=006b7615-7f41-47af-af1d-c4299924f224

This returns the hospital and Location B and Location C.

Starting at the bottom of the tree (Location 3 from my example)

https://{host}/Location?_include=Location:partof&_include:iterate=Location:partof&_id=07238beb-e53d-4225-9320-9f8b6668864f

This returns the room and Location B and Location C.

[liamwilson-kainos]

Could we extend the Azure FHIR documentations to provide this example on how to use the :iterate modifier with _include or _revinclude when traversing a reference hierarchy?

[EXPEkesheth]

This is a good suggestion; we will add an example to Azure documentation.