I’m relatively new to the HL7 scene having implemented a few V2 messaging solutions (A08 , A19, ORU) and the V3/CDA work on PCEHR. I am trying to get my head around FHIR. So far I am stumped in how I would go about for example implementing the various trigger/messages I have done in V2. Is there any guidance? I cant find much. Is that because the objective of FHIR is implementers are free to do it anyway they like? If you could send me some links that would be a good starting point that would be great
Most implementers of FHIR use the RESTful interface. In this approach, there’s no messaging events: you just post the Patient, Encounter etc resources directly to the server. The resources contain the new state of the Patient/Encounter etc, and the server (or any system subscribed to the server) infers the events as needed.
A few implementers use the messaging approach. In this case, the architecture works like v2 messaging, with triggers, and events. However, because the resources are inherently richer than the equivalent v2 segments (e.g. see Patient.link), we didn’t need to define a whole set of A** messages, like in V3. Instead, there’s just “admin-notify” in the event list.
For XDS users (HIE or the PCEHR in Australia), see IHE’s Mobile Health Document Specification.