Resource specializations

Question

The FHIR schema defines very generic Resources that would sometimes represent several concepts in an implementation and the meaning of the resource is difficult/impossible to determine from the object itself. For example the Condition resource may represent a problem on a problem list, an admission diagnosis, a final diagnosis, a primary diagnosis, etc. The meaning of the Condition depends on know which of these it is. Is there a way to make this explicit in FHIR?

In some cases a Profile StructureDefinition could be used to distinguish between specializations of a Resource, but this doesn't work for things like final vs. admit diagnosis since these contain the same data (i.e. there is no discriminator) and so it is not a general solution.

Answer 1

Profiles never change the meaning of an instance, they simply identify constraints that an instance adheres to. If you stripped out all profile ids from an instance, you could put them back if you had access to all of the eligible profiles and compared them against the instance.

Admission diagnosis or final diagnosis isn't a type of diagnosis, rather it's the relationship of a diagnosis to a particular encounter. A diagnosis that is the final diagnosis of one encounter might be the admission diagnosis for another. A Condition might be included on a problem List whether it's a complaint, symptom, finding or diagnosis. The notion of primary vs. secondary is also a relationship with respect to an encounter/billing. The primary diagnosis for encounter A might be a secondary diagnosis for encounter B.

Look at Encounter.admittingDiagnosis, Encounter.dischargeDiagnosis and Claim.diagnosis.sequence to differentiate admission/discharge and primary.

(It would probably be good to include this guidance on the Condition resource itself, so feel free to submit a change proposal using the link at the bottom of the spec :>)