Message Specification

Product Vision Statement

For producers and consumers of pathology diagnostics within the NHS

Who need federated sharing of pathology requests and results

The Fast Healthcare Interoperability Resources (FHIR) pathology message realises an information model that structures SNOMED CT coded elements of the pathology request, investigation and reporting process whilst preserving the relationships between the process components.

That is the current recommended interface serialisation method for modern healthcare systems


This product - FHIR - carries the data model which has been mapped to published FHIR resources and their attributes, is compatible with SNOMED CT, is easily implementable and supports RESTful request & response transactions.


The Pathology Message Specification defines a set of draft HL7 FHIR STU3 profiles to support the electronic exchange of pathology test results. Together with the Unified Test List and standardised Units of Measure, the specification aims to provide an interoperable and machine-readable mechanism for sharing pathology test results.

The initial objective is to use the FHIR message specification (in conjunction with the Unified Test List and standardised Units of Measure) to replace the existing PMIP EDIFACT messaging standard that is used for Primary Care requested test results.

Information Model to Message Specification Mapping

As part of the development of the Pathology Message Specification, the business entities described in the Pathology Information Model were mapped to equivalent FHIR profiles. This mapping is summarised below:

  • Test Request Summary - This business entity contains information relating to the requested test(s). It maps to the ProcedureRequest FHIR profile.
  • Test Report - This business entity contains the overall findings and clinical interpretation of one or more test results. It maps to the DiagnosticReport FHIR profile.
  • Specimen - This business entity contains details of the specimen(s) provided for testing. It maps to the Specimen FHIR profile.
  • Test Group - This business entity is used to define a group of related tests, for example a Full Blood Count. Test groups are often referred to as batteries, panels or profiles. It maps to  the Observation FHIR profile.
  • Test Result - This business entity contains information relating to a single test result. It maps to the Observation FHIR profile.

The business entities representing the Requester / Requesting Organisation, Performer / Performing Organisation and Specimen Collector / Specimen Collecting Organisation map to the Practitioner and Organization FHIR profiles respectively. The Patient business entity maps to the Patient FHIR profile.

The high-level relationship between the business entities and corresponding FHIR profiles is illustrated in the following diagram:


Implementation Guidance

Further information relating to the Pathology FHIR profiles, including a description of the messaging architecture and example messages, is provided in the following draft Implementation Guidance:

Microbiology Reporting

The following presentation slides outline the proposed design approach for supporting Microbiology reports using the existing Pathology FHIR profiles: Presentation slides

The slides reference the following example FHIR message (for a Microscopy, Culture and Sensitivity report): Example FHIR Message

Additional Use of Pathology Related FHIR Profiles

In addition to their use as part of the Pathology Message Specification, the pathology related FHIR STU3 profiles are also used by several other NHS Digital projects and programmes.  These are summarised below.

National EDIFACT-FHIR Adaptor: this provides a way for GP systems to receive EDIFACT (NHS003) based lab test result messages using a FHIR interface.  Further details can be found here:

The following document is also of note:

This test report provides an overview of the tests that were performed by a GP system supplier during testing of the adaptor and a summary of the outstanding defects.

GP Connect: a GP Connect variant of the pathology related FHIR STU3 profiles are used to support the retrieval of pathology lab results from GP systems.  This forms part of the GP Connect Access Record Structured FHIR API.  Further details can be found here: and here:


  • Liaised with internal stakeholders to understand potential options around adding additional content and improvements to the message. 

  • Commenced message curation with INTEROPen, February 2019 with GP Connect and GP to GP programmes 

  • Internal design activity completed prior to the start of curation 

  • HL7 FHIR message specification and implementation guidance published.

For previous Done / Planned milestones please visit our Newsletter Archive.