Profiling Conventions & Approach
pCHDCF Translation Practices
This section will continue to expand in future iterations as content is further developed in the pan-Canadian Health Data Content Framework (pCHDCF). This version focuses on 1) mapping the data element definitions from the pCHDCF Data Content Standard, 2) outlining a potential logic for translating initial expectations into FHIR profiles, 3) initial introduction of terminology for select concepts.
Mappings to the Data Content Standard data elements are defined in-line within the profiles and can be found on each profile's page.
Translating Obligations
In line with General Principles & Design these profiles make use of an emerging a new (and evolving) mechanism in FHIR that provides a consistent and machine processable way for profiles to define their expectations for system behaviors. This mechanism is the Obligation Extension which is defined in the cross-version extension registry but has been recently expanded to support application. The updated definition can be found in the CI Build FHIR Extension Registry definition.
The Data Content Standard (DCS) does not currently include requirement strengths (e.g., mandatory, required if known, optional) but the following definitions have been proposed to convey the level of expectation for a concept in a given context:
- M = Mandatory: where the data element is mandatory, and the process cannot be completed without the data element being present.
- RK = Required if Known: where the data element is required to be provided if available or known to support the process.
- O = Optional: where the data element is not required and may be provided to support the process.
These definitions and the approach in the Data Content Standard towards applying these requirements may continue to evolve.
In the meantime, the definitions above have been translated to the following obligation codes:
| pCHDCF Strength | Target for Expectation | Obligation Code |
|---|---|---|
| Mandatory | Resource Producer | SHALL:populate |
| Mandatory | Resource Consumer | SHALL:handle |
| Required If Known | Resource Producer | SHALL:populate |
| Required If Known | Resource Consumer | SHALL:handle |
| Optional | Resource Producer | SHALL:able-to-populate |
| Optional | Resource Consumer | SHALL:no-error |
Additional considerations:
- Some expectations are expected to be nested/conditional; others will require the backbone element carries the same strength
- Optional elements identified as stretch goals may not carry the SHALL:able-to-populate obligation (e.g., National Unique Health Identifier). These will be socialized with a comment until further is known about expectations for consumers/producers.
Note: The CACDI (Canadian Core Data for Interoperability) has recently been announced as a new artefact in the pCHDCF that will define the standardized set of essential health data elements and associated value sets within the context of a common architecture. The CA Core+ will package the CACDI into a set of core FHIR profiles to support interoperability and data exchange.
Obligation logic is temporarily removed from the CA Core profiles, and will be reapplied pending the release of CACDI. This will allow further refinement to cross-version use of Obligations and it will allow for the logic to be updated to ensure alignment with the exchange expectations that will be driven by the CACDI.