During the past few HL7® quarterly FHIR® Connectathons and Workgroup Meetings, the FHIR community has been debating the impact of what I’m calling “version collisions:” when someone makes a FHIR request for healthcare data expecting that they will receive a response conforming to US Core 3.1.1, but they receive a response with data conforming to US Core 4, 5 or 6.
Given ONC’s recently released HTI-1 language proposing the move to US Core 6.1.0 by January 2026, whereas most FHIR IGs point to US Core 3.1.1, these questions are now especially relevant.
- Does the responder even know what version of US Core the requestor is expecting? Should they?
- Will the responder refuse to send back a response if they know it won’t match these expectations?
- If the requestor receives a response conforming to a different US Core version than they expect, what happens? What should happen?
- What is the impact of these “version collisions” on clinicians and patients?
We plan to collect objective data to inform the debate by observing what happens and measuring the result.
Join us in the Testing – Measure the Impact of US Core Version Differences track at this month’s virtual HL7 FHIR Connectathon.
I hope to see you (virtually) there!