NCPI FHIR Implementation Guide
0.2.0 - ci-build
NCPI FHIR Implementation Guide - Local Development build (v0.2.0). See the Directory of published versions
While this IG assumes that the reader is already proficient with FHIR resources and the overall model, basic overview will be provided here for key concepts that are heavily relied upon throughout the IG itself.
FHIR is a sophisticated API and the documentation may be a bit opaque on the first pass. There are resources available to help those interested in learning more to get up to speed.
FHIR 101 is a tutorial inside a Jupyter notebook that was put together by some folks at the Kids First Resource Center.
Terminology has always been a fundamental part of knowledge exchange and it’s importance is even more salient than ever. FHIR addresses the need with a handful of resources:
FHIR defines related codes by enumerating them inside a CodeSystem. The CodeSystem will have a unique url property to establish it’s functional identity, and codes from that CodeSystem will typically carry that url as the code’s system property to establish the code’s origins (and thus it’s true meaning). Many times, each code will be accompanied by a display which provides a more human readable representation of the code and possibly a definition which may provide additional clarity about the code’s intended use.
Codes within a CodeSystem can optionally be arranged hierarchically.
A CodeSystem acts as the definition of a set of codes which have a common system (the url). A ValueSet, on the other hand, is a collection of codes that is defined for a specific purpose (binding). The members of a ValueSet do not have to originate from the same CodeSystem. One might want to bind a specific Condition profile’s code property to a fixed set of codes from one or more public ontologies. This would be done by adding the members to a specific ValueSet and binding it to the code property in the profile.
A Coding is a FHIR data type that describes a single code. In addition to the code property, it will usually include a system and possibly the code’s display property.
A CodeableConcept is a common data type in FHIR that allows a resource to attach one or more Codings. A typical use for multiple Codings is to provide terms from other ontologies that represent the same concept.
The ConceptMap provides the FHIR server with mappings from a source code to one or more related codes. Client applications can then utilize the $translate function to list all codes mapped to a particular code.