Demographics

openEHR distinguishes between a demographic domain and the EHR domain. The EHR domain contains clinical EHR data, while the demographics domain usually contains non-clinical data. The initial idea behind this separation was to address privacy concerns. What constitutes non-clinical data varies between vendors and use cases.

In the EHR domain, everything relates to a patient’s EHR, whereas the demographics (or non-clinical CDR) usually contains patient demographic data such as full name, address, insurance number, etc. There are cases where EHR archetypes contain patient-related data, particularly in research contexts. For example, birthdate, gender, and sex are stored.

Vendors typically manage demographic data using either a FHIR server or an openEHR demographics server (based on openEHR demographics archetypes). The reference model of the EHR links these external IDs.

FHIRconnect logic sends individual FHIR resources to a demographics endpoint and links them accordingly. This endpoint, located outside FHIRconnect, can either transform these resources or use FHIR directly. The key requirement is that it returns an external identifier, which is then linked in the openEHR files and also can be used to re-retrieve the fhir resource for tranforming it back.

This process involves mapping resources to RM paths that reference demographic data. If the referenced resource is included in the Bundle, it is sent to the demographics service, and the returned ID is stored in the PARTY_IDENTIFIED (or DV_IDENTIFIER) field. Otherwise, the resource’s identifier is directly linked inside the RM field, since there is nothing to transform. FHIRconnect performs this operation for each path containing a PARTY_IDENTIFIED field. When extracting FHIR data, the ID is requested from the demographics service and the resource received back, returned.

Example

  - name: "partyIdentifiedComposer"
    with:
      fhir: "$resourcePath.recorder"
      openehr: "$composition/composer"

Flow from FHIR to openEHR

demographics1.drawio

Flow from openEHR to FHIR

demographics2.drawio

If a demographics service is not implemented, a FHIRconnect engine should use the IDs maintained by the FHIRconnect engines FHIR-server.