Add section to explain use of OperationOutcome

[nathanbunker]

http://jira.hl7.org/browse/fhir-24949

How should an immunization CDS engine respond if the patient or immunization information had logic errors that prevented calculating a proper response? For example if the administration date for the immunization was before the birth of the patient or the vaccination code was not recognized by the receiving system? In these cases it might not be possible to produce a sensible result or the result may be missing critical information. How does the server signal properly to the requestor that it was unable to respond and the reason why? Suggested by Brian Lee at STC.

raig - I agree that we should comment on this, but I'm not sure what the answer is. I would imagine that there is a general response to any operation that fails. Is the answer to respond with an OperationOutcome and/or DetectedIssue? The operations page says "An HTTP status code of 4xx or 5xx indicates an error, and an OperationOutcome SHOULD be returned with details.".

Eric - I looked into this when we were creating this and that was my understanding too Craig is that this is part of the standard and OperationOutcome should be used. Maybe we just need to connect the dots for the readers on where to find OperationOutcome? Unless we plan to get much more specific about our error codes.

Nathan - Brian Lee has created an example implementation that returns these types of outcomes and has proposed a list of these outcomes. These have been placed into confluence for discussion and review by the group: Ballot #2 Operation Outcomes https://confluence.hl7.org/pages/viewpage.action?pageId=66927793

[nathanbunker]

Need to find out where this should go.