Health Level Seven (HL7) has been developing healthcare
information exchange and related standards since 1987. In that time, the organization has
produced a number of standards families - many used throughout the world to automate healthcare
data sharing and improve patient care. FHIR has been written to be implementable without
any knowledge of these other specifications. However, FHIR does leverage this prior experience,
both in terms of applying best practices learned from experience and attempting to avoid
some of the pitfalls of earlier work.
This appendix describes the relationship of FHIR to some of HL7's other standard families.
It may be of interest to those coming to FHIR with previous experience with other HL7
standards as well as those who may need to support interoperability between FHIR
solutions and implementations of other HL7 standards.
In addition to the major standards families identified below, HL7 produces numerous
implementation guides, some of which have earned as much prominence as a standard
family themselves. The general guidance given below for each standard family should
hold for all implementation guides based on that standard. For example, the guidance
listed for CDA would apply to Consolidated CDA (CCDA) and other CDA Implementation Guides.
While this appendix focuses on the relationship between FHIR and other HL7 standards,
relationships also exist to non-HL7 standards. Some resources provide direct implementation
of functionality from other standards including DICOM
(see the ImagingStudy resource) and IHE
(e.g. the AuditEvent and DocumentReference resources).
Many FHIR resources draw requirements from or provide mappings to other standards. Some resources also
provide additional guidance on how to use them with external specifications as part of their implementation notes.
As well, there are chat.fhir.org streams exist dealing with CDA and FHIR
and v2 and FHIR .
You can check the stream list or ask on the
implementer's stream for guidance about FHIR and other specifications
FHIR can satisfy the needs covered by all of the previous primary HL7 interoperability standards (HL7 V2 , HL7 v3 and
CDA). In many cases, it also provides additional benefits in terms of ease of interoperability. Therefore, the
possibility exists that FHIR could gradually replace some or all of these standards. However, it is unclear how
rapidly (or even if) the market will make such a migration. It is likely that most of these standards will exist
in parallel for quite some time. HL7 has committed to ongoing maintenance of existing standards for as long as
the HL7 membership requires.