Overview and Maintenance

The section details the terminology that is used in the Messaging Standard. The migration from the CPHA standard to FHIR will impose some changes in terminology (field values); however values will only change when necessary in order to be conformant with the FHIR standard and to ensure that there is synchronization with other FHIR standards within the same domain in Canada.

The FHIR Profiles will identify terminology bindings for data elements that specify a data type of "code" or "codeable concept". For example, the Patient.gender field has a binding to the HL7 value set,called Administrative Gender and the link to the value set is found in the profile.

Bindings (found in the profiles) are always to a "value set", which can be made up of values from multiple "code sets". It is the "code system" that is specified in the message. For example, we can create a value set called "PrescriptionMedicinalProduct" that can include values from the DIN, CCDD and NPN code sets. In the message instance, where medication codes are sent, the code is specified along with the code "system" as this combination ensures global uniqueness.

Binding Strengths are an important concept to understand in FHIR. Required bindings do not allow any codes to be added to the code set. The official definitions for Binding Strengths are found here for those interested.

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Terminology Maintenance Process

Terminology, also known as "vocabulary" or "field value sets" will change from time to time in some cases. A terminology maintenance process will be put into place to ensure that all implementers have access to terminology updates on a timely basis. More common updates will include error codes, service codes and DINs/CCDDs.

It is important to note that terminology can be updated without updating the messaging standard. It will be rare, if ever that a terminology update will trigger a new "version" of the message specification. The "publication" will be updated but the message version will remain unchanged. For example, if an error code is added, there will be an updated specification but it will not cause an update to the message structure and is considered a "non-substantive" change.

This project will not publish DINs or other medication codes as Pharmacy vendors are aware of updates to this code set as they are published by the source, Health Canada.

The Complete Terminology List identifies the owner of the code set. Some code sets are owned and managed by PCS FHIR, such as the ones that have been inherited from CPHA3. Others are managed externally by HL7, Canada Health Infoway or other parties such as Health Canada or SNOMED.

Approach for MVP - Initial Rollout

DUR Messages For initial implementations that are based on the MVP scope, the codes that are in use today will not change. It is recognized that it in a future state, splitting out DUR messaging from regular messaging is desirable.

The standard will support DUR specific messaging. Adjudicators can start to use this post MVP. Vendors will look in both places and adjudicators will send DUR specific messages when possible

Response Codes The response codes that are used today come from CPHA, PEI NeCST, Saskatchewan Pescription Drug Program and SAAQ in Quebec. The FHIR Response code list will be extended to support all of these value sets. A code system has been added in order to distinguish between code sets.