This is the current version of the PS-CA Implementation Guide. Other releases of the PS-CA Implementation Guide may be found on a table on the Home Page of this Project.

Known Issues & Future Development

This Implementation Guide is part of a public comment release of the PS-CA Specification, intended for review, socialization, and feedback in preparation of PS-CA Version 1.0 for Trial implementation. During development, several issues were detected that could not be resolved in time prior to publication; issues with multiple—but no "best"—solutions possible; and issues with conflicting guidance. Some of those issues are listed below. Open issues are those for which no decision has been made, are pending feedback, or, for which there is an outstanding action. Issues are marked as close when a decision has been made, or the issue resolved.

Feedback is requested on both open and closed issues. Instructions for feedback submission can be found at Specification Feedback.

Known Issues

  1. Validation Tooling - Expanding Value Sets / Intersectional Value Sets

    There are two tooling issues leading to IPS value sets not being expanded and validated against by current FHIR tools:

    1. The is a current limitation in Simplifier validation tooling to perform expansion and filter capabilities that are necessary for the validator to determine if a slice is met on loaded examples.
    2. More broadly, there is a known issue with the FHIR Validator Tooling/FHIR terminology server that the validator uses (tx.fhir.org) not supporting value sets that combine multiple value sets and/or apply filters as part of the sequence for defining the value set (an approach IPS uses for many of its value sets).
      • After this fix is applied, Implementers will be able to validate the examples including IPS value sets against the FHIR Validator GUI - IG Package is loaded and can be validated against by selecting "Options" and then choosing "https://packages.simplifier.net/ca.infoway.io.psca" from the dropdown of Implementation Guides.

  2. Referenced ValueSets and CodeSystems are not resolvable.

    Some referenced ValueSets are not available at their canonical URL; some (particularly Canada-specific) ValueSets are not on the terminology servers used in IG publication (i.e. tx.fhir.org). Some referenced ValueSets are not currently available as FHIR R4 and may require conversion before use. Primarily, these issues impact validation against Canada Health Infoway-hosted ValueSets during development of derived Implementation Guides. (This doesn't affect deployed systems, since, in that environment, instances will be validated against locally present value sets.) For several of these ValueSets, "stub" resources have been created to stand-in within this Implementation Guide for the unresolvable ValueSets.

    Current guidance is to manually download the referenced value sets from, for example, the Terminology Gateway. Investigation is needed to determine if the problem ValueSets can be made "resolvable" through Infoway, or if they can be added to the standard terminology servers.

  3. Must Support relaxation

    Several elements flagged as Must Support in IPS-UV are not flagged in PS-CA due to feedback received about jurisdictional support. These elements are called out on relevant profile pages in this implementation guide. Feedback is requested about:

    • Whether it was appropriate to relax the Must Support requirement for these specific elements
    • Whether Must Support should be relaxed or added on additional elements

  4. AdditionalBinding Rendering

    This version introduces the AdditionalBinding Extension which has been utilized by IPS since the IPS 1.1.0 release to convey additional terminology that is relevant under certain contexts (e.g., proposed for use with countries that do not have SNOMED CT licensing, utilized heavily in legacy data, etc.). See Profiling Conventions and Approach.

    • This extension is applied to the binding element and renders in IGPublisher but does not currently render in Simplifier. A ticket has been submitted. In the meantime, the profile pages under FHIR Artefacts and the FHIR Artefacts page have been updated to indicate the terminology indicated as additional bindings.

  5. individual-RecordedSexOrGender

    This version socializes the RecordedSexOrGender Extension but current tooling requires for it to be "re-published" in this guide to pre-adopt an extension published in R5. This extension is an R4 (4.0.1) conversion of the canonical extension published in the R5 FHIR Extensions Pack. Implementers are advised to take note that the data type for the extension part sourceDocument (Reference) is not forwards compatible to the R5 type for that part (CodeableReference). No other material differences are present between the R4 extension published in this guide and R5 extension published the FHIR Extensions Pack.

Note: To view previously closed issues please review prior versions of the PS-CA. You may find the previous versions of the guide here.