NHS North West Genomics - Local Development build (v0.2.1) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions

Exchange

graph LR;

subgraph Producer;
    s[Source]
    s --> v2E
    s --> v2D
    v2E["HL7 v2 Event Message"]
    v2D["HL7 v2 Document Message"]
    s --> fMessage["FHIR Message (Document)"]
    s --> fEvent["FHIR Message (Event) and Subscription"]
    s --> rest["FHIR RESTful (PUT/POST) and Transaction"]
    rB[Consumer Business Logic]

    rest --> rB
    Agg["FHIR Document<br/>(Aggregation Layer)"]
    Agg --> s
end 

subgraph Consumer
    B[Business Logic]
    d[Desination]
    B --> |"FHIR RESTful (PUT/POST)<br/>Optional"| d
    d --> restC["FHIR RESTful (GET)"]
end 

v2E --> B
v2D --> B
fMessage --> B
fEvent --> B
rB --> d
restC --> s
restC --> Agg

classDef pink fill:#F8CECC
classDef green fill:#D5E8D4;
classDef yellow fill:#FFF2CC;

class restC,v2E,fEvent,Agg green
class rest,rB pink
class v2D,fMessage yellow

HL7 v2 is the most common exchange format for healthcare data. It has two basic interaction styles:

• Event Message for reliable, asynchronous event notification between applications e.g. ADT and MDM_T01 events
• Document Message to reliably transfer a data structure (orders and reports) between applications, e.g.ORM_O01, OML_O21, ORU_R01 and MDM_T02

HL7 FHIR has several interaction styles which can replace HL7 v2.

• FHIR Message (Document) which for orders and report messaging, is a direct replacement of HL7 v2.
• FHIR RESTful (GET) which provides a read only API to the source data. This is one of the most common interaction style using FHIR.
• FHIR Message (Event) and Subscription is a modernised version of HL7 v2 which focuses on event notifications only similar to HL7 v2 ADT and MDM_T01 events (but not orders and reports).
• FHIR RESTful (PUT/POST) which provides a read and write API to the desintiation data. Note this moves the consumer business logic to the consumer and so can be considered an anti-pattern for enterprise level exchanges.

Like HL7 v3 CDA, FHIR also supports a clinical document model called FHIR Document