FHIR R6 is getting closer.
The deadline for changes is November 1st – less than three weeks from now.
If you’re currently invested in R4, how significant are the changes coming in R6?
Here’s the current change log: https://build.fhir.org/diff.html
It’s a fantastic document, clearly outlining the changes to each resource and to each element. The color coding makes it easy to follow.
- White for changes to elements
- Green for new elements
- Blue for moved or renamed elements
- Red for deleted elements and resources.
What might these changes mean for your app or solution?
- New elements (green) should not require much work.
- Moved or renamed elements (blue) may require minor code changes.
- Deleted elements (red) will require bigger changes.
Element changes (white) are easy to miss as their lack of color is suggestive of no change at all.
But it’s in these elements that I feel the real work lies.
Here’s a snapshot from the Encounter resource.
Four codes were removed from Encounter.status: arrived, triaged, onleave, finished.
They’ve been replaced by four new codes with different meanings: on-hold, discharged, completed, discontinued.
What does this mean for existing logic and data flows that depend on “triaged” or “arrived” statuses?
Here’s another example.
Encounter.class’s cardinality was changed from 1..1 (mandatory) to 0..* (not mandatory and there can be more than one).
If your app is relying on a single Encounter.class always being there, then this is a big change that will require discussion with your consumers and data providers.
It’s non-trivial.
These changes are all being made for good reasons and after much debate, discussion and feedback. But this should not distract from the impact a migration from R4 to R6 will have on existing apps and solutions.
Migrating will be more than just “updating code”.
Processes, data flows, logic, dependencies and expectations – all the way up and down the chain will have to change.
It’s a very big deal.
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