Encounter search parameter confusion

[Brett Murray]

We're trying to search the Encounter resource to pull back all encounters for a Patient with a specific MRN value.  I'm not sure how to format the search parameter to make this work.  

From the Cerner spec:

https://fhir.cerner.com/millennium/r4/base/management/encounter/#search

GET /Encounter?:parameters

How do we use the 'patient' parameter to specify a patient 'identifier' and not an '_id'?  Test patient Nancy Smart has an MRN value of '6930'.  Thought the following GET call would work, we're getting "text": "patient: invalid reference format" in the response.

https://fhir-open.cerner.com/r4/ec2458f2-1e24-41c8-b71b-0e701af7583d/Encounter?patient=urn:oid:2.16.840.1.113883.6.1000|6930

Any help would be greatly appreciated!

Thanks,

[Aaron McGinn (Oracle Cerner)]

You will have to do a Patient lookup (by identifier, if necessary), then use the Patient.id as the Encounter search's patient parameter.

-Aaron (Oracle Cerner)