The FHIR standard provides a mechanism to specialise and extend FHIR resources through the creation of “profiles”.
In England, we are developing profiles according to the below “levels”:
- Level 1: These are the base FHIR resource profiles defined by HL7 international
- Level 2: These are referred to as ‘Care Connect Profiles’ and are England-wide profiles curated through the INTEROPen community, and published on the HL7 UK FHIR reference server
- Level 3: These are implementation-specific profiles for a particular system or domain. For NHS Digital these are published on the NHS Developer Network FHIR Reference Server
NHS Digital has agreed to base any profiles on the Level 2 profiles where these exist (see requirement FHIR-NAT-02).
In addition, the following requirements have been agreed:
All FHIR resources (Level 1 profiles) have a numeber of fields defined as ‘summary’ fields, which appear in results when the client requested summary versions of the resource to be returned (for example in search results). These summary fields can only be defined in Level 1 profiles and cannot be changed in Level 2/3 profiles.
Note: This is a rule established by HL7, but is not clear in the HL7 FHIR specification.