Allow multiple RelatedPerson Resources with same Identifier

Nottinghamshire County Council have identified a bit of a blocker when developing their data feed for RelatedPersons. The issue arises when they have multiple patients who all have a relationship with the same person … for example:

• Mavis has a Daughter Sarah, who is her Main Carer and NoK

• David is married to Sarah, is wife is his NoK

• Claire is Sarah’s Daughter, her mother is an Emergency Contact

In order to model this in FHIR, we would need to create 3 instances of a RelatedPerson, each referencing one of the 3 Patients, with the details of the specific relations and roles between the two individuals.

The issue relates to adding a local identifier for the RelatedPersons …

…hence, in the examples above it would be:

https://fhir.yhcr.nhs.uk/Id/local-RelatedPerson-identifier|511.54321

Currently, the default settings in the Connect FHIR Appliance will prevent providers from being able to create multiple instances of the same resource with the same Identifier, and hence will respond with a 500 internal server error (due to a database constraint violation error) when attempting to create the second and third RelatedPerson instances. (note - this is a different code to a duplicate Patient Resources with same Identifier, that receive a 409 status)

That validation makes sense on the likes of Patient, SocialCareServices and SocialCareAssesment, as we would not expect to see two resource instances with the same business identifier in the same appliance. However, I don’t believe it shouldn’t apply to RelatedPerson identifiers, which relate to the actual person, not the specific instance of the RelatedPerson resource (which detail the roles and relationship to a specific patient). Even the current version of the FHIR Implementation Guide has a note to this effect.

Although there is a hidden setting in Connect (ALLOW_DUPLICATE_IDENTIFIERS=true), we would not want to enable that because it would not identify genuine duplicates, e.g. on Patient Resources.