Relationship to Other Specifications

In every national health information exchange ecosystem – there is a landscape of standards that provide rules and guidance that influence the design and behavior of systems.

National Core profiles make up one layer of specifications that, when combined with other specification layers, ultimately drive and harmonize foundational system capabilities for FHIR exchange within a country.

The intent of this section is to describe how the profiles in the CA Core+ project relate to other specifications and provide reviewers with the details on how they will be leveraged by other specifications as they become more stabilized.

pan-Canadian Health Data Content Framework

The pan-Canadian Health Data Content Framework (pCHDCF) defines and models person-centric health data. The framework is technology-agnostic, which means it will support data being exchanged across various technologies and systems.

FHIR profiles under the CA Core+ Project are direct interpretations of the constraints outlined within the contents of the pCHDCF, particularly the Canadian Core Data for Interoperability (CACDI). The CACDI aims to define a standardized set of essential health data elements and associated value sets in the context of a common architecture to support interoperability and data exchange across the Canadian healthcare ecosystem. The development of CACDI will follow an iterative design process and will expand over time.

Note: Prior versions of the profiles socialized mappings to the broader Data Content Standard (DCS) though this has been replaced now that CACDI artefacts are in development.

The Common Data Exchange profiles in this guide (see General Principles & Design) express the foundational expectations towards data elements that FHIR servers and clients supporting Primary Health Care (and eventually additional care domains) are expected to be able to support.

For example, if the pCHDCF CACDI includes expectations that the Birth Date concept is part of the patient details needed to support a broad range of use cases, the profile in this guide (e.g., Patient CA-Core) would expect FHIR Servers sharing their data to be able to demonstrate their system is capable of including patient.birthDate in a FHIR message that the system produces.

See section below on Domain-Specific Data Exchange Specifications for details on how the CACDI/CA Core Profile structure will be leveraged in contexts like Patient Summary, eReferral, etc.

CA FHIR Baseline

The Canadian FHIR Baseline is a use case agnostic baseline specification that expresses the lowest common denominator of constraints and localized concepts that are shared across published profiles in the Canadian FHIR Registry.

While the Canadian FHIR Baseline is a specification developed through the grassroots volunteer efforts of Canadian FHIR implementers, the content has become widely familiarized with the Canadian FHIR community as a starting point for profile authors to begin the process of soft-harmonization with each other's work.

In alignment with the distinction between Base, Baseline, and Core profiles, the intent of the CA Core+ profiles is to meet (and exceed) the expectations of the Canadian FHIR Baseline, ultimately identifying more prescriptive constraints that progress the adoption of Common Data Exchange requirements and Domain-Specific Data Exchange requirements outlined in the pan-Canadian Health Data Content Framework.

This standard makes use of the CA FHIR Baseline in the following ways:

• claims a dependency on the CA FHIR Baseline Implementation Guide to make use of its artefacts (e.g., extensions, value sets, etc.),
• imposes the Baseline constraints on the relevant CA Core+ profile through use of the imposeProfile extension

To learn more about the Baseline and its benefits, or to contribute to advancing the maturity of the Canadian FHIR Baseline Profiles, please visit Canada Health Infoway’s FHIR Implementers Working Group here.

CA:FeX

The Canadian FHIR Exchange Specification (CA:FeX) outlines the expectations for the initial set of search parameters and resource exchange capabilities that FHIR Servers in Canada are expected to support. While some guides like US Core combine the conformance requirements for profile support with the conformance requirements for interaction support, these requirements are separated into their own specifications in Canada (CA Core and CA:FeX respectively).

While it is expected that many servers will support both CA Core and CA:FeX, this separation is pursued at this stage to allow implementers more granularity in their testing activities and conformance claims (e.g., CapabilityStatement.instantiates populated with the distinct guides they support). This separation also allows both specifications to easily differentiate between content maturity (since CA:FeX was published first and has had more exposure through public review and testing events).

Domain-Specific Data Exchange Specifications

Domain-Specific Data Exchange Profiles are intended to identify constraints that are applicable and expected under certain contexts (e.g., Patient Summary).

All Domain-Specific Data Exchange FHIR Profiles (see General Principles & Design) are expected to leverage and impose the constraints of the Common Data Exchange Profiles.

For example, if the pCHDCF Data Set for Patient Summary further expected that the CACDI Birth Date concept always be present in the context of a Patient Summary, then the Domain-Specific Data Exchange FHIR Profile (e.g., Patient PS-CA) would also add a cardinality constraint (e.g., minimum cardinality of 1) and an expectation that FHIR Servers also demonstrate they always include Patient.birthDate when a value is known and allowed to be shared (e.g., isn't masked for privacy reasons).

Domain-Specific Data Exchange profiles are expected to be housed in their respective guides (e.g., Pan-Canadian Patient Summary (PS-CA) IGuide). Due to the efforts of the pCHDCF and CA Core+ initiatives starting after some pan-Canadian data exchange initiatives (e.g., PS-CA, eReferral & eConsult) were already underway, the content in the respective pCHDCF Data Sets will be heavily informed by the requirements defined through the work to date. Any potential refinements from the pCHDCF data sets will be socialized and refined through the heavy collaboration between the teams facilitating the pCHDCF and pan-Canadian data exchange initiatives.

The comparison between the early subset of Common Data Exchange Profiles and the Domain-Specific Data Exchange Profiles is already occurring informally. However, once the CACDI and Data Sets have stabilized and undergone a formal release (e.g., 1.0.0), the imposeProfile extension is expected to be applied within the Domain-Specific Data Exchange profiles in order for them to inherit and enforce the foundational expectations from the profiles in this guide.