Background

The CA:SHL specification is a Canadian Interoperability Specifications (indicated by the CA: prefix) based on the HL7 Health Links Specification, currently in the process of being contributed to IHE (Integrating the Healthcare Enterprise), with the aim of becoming an internationally adopted Integration Profile. As part of this transition, the names of the profiles, actors, and transactions are subject to change and align with international standards and conventions.

Note that Shareable Health Link is based on HL7 SMART Health Links and often can be used interchangeably, Shareable Health Links offers an Integration Profile around SMART Health Link, with the goal to provide implementers with a set of building blocks using the Actor and Transaction paradigm, and a consistent way to conformance test their implementations.

Security Considerations

When creating, sharing, and consuming clinical data using CA:SHL, it is crucial to also ensure the privacy, authenticity, and integrity of the information through encryption and digital signatures. 

• Specific details regarding the privacy, authenticity, and integrity of the information are not within the scope of this specification. However, implementations that do not employ high-level security measures, such as digital signatures and robust encryption, are not recommended and are strongly discouraged.
• CA:SHL is the subject of international collaboration at IHE International, with the IHE ITI committee approving the initiative to evolve SHLinks and advance it into Verifiable Health Links, by adding a structured and robust security approach in future iterations.
• While trust framework considerations are critical, they fall outside the scope of this specification. Implementers should ensure that any exchange of SHLinks is governed by a robust trust framework that ensure security and provenance.
• CA:SHL is a building block that is meant to be used together with added security measures, otherwise it is not suitable for exchange in environments where security and provenance cannot be reliably established by other means.

Standard Version

The CA:SHL Profile is based on:

HL7 Health Links Specification: version 1.0.0-ballot (2024-08-08), based on FHIR v4.0.1: R4. This is part of the proposed STU1 version of the SMART Health Cards and Links FHIR IG for ballot in September 2024. 

Acronyms

CA:SHL – Canadian Shareable Health Links (CA:SHL) Interoperability Specifications

SHL, SHLink – Shareable Health Link, containing access point to the patient’s health data (often encoded in a QR code format). 

SHLink Clinical Data - Clinical data associated with the SHLink

Overview

Shareable Health Links (CA:SHL) is a Canadian Interoperability Specifications based on the HL7 Health Links Specification, that defines building blocks enabling patients to generate shareable links that encode their health data such as patient summaries or immunization records. These shareable links can often be downloaded onto their devices and converted in a QR code format, facilitating patient-mediated data sharing and interoperability within the healthcare ecosystem.

The following are some examples of the benefits of SHLink:

• Enables patients to create, share, and manage their health data using standardized operations based on HL7 standards.
• Facilitates convenient access to health information through easily shareable links, such as QR codes.
• Enhances patient control over their health data, allowing them to decide who can access their information.
• Promotes seamless coordination and collaboration among healthcare providers by providing timely and accurate health information.
• Supports improved continuity of care through efficient data sharing during patient transitions across different care settings.

Actors and Transactions 

The following diagram provides an overview of the CA:SHL Actors, Transactions and their interactions that are currently in scope.

The table below lists the transactions for each actor directly involved in CA:SHL. To claim compliance with CA:SHL, an actor shall support all required transactions (labeled “R”).

Transaction Details

• Generate SHLink [CA:SHL-1] – This transaction sends a Generate SHLink Request from an SHLink Requester to an SHLink Creator, using an HTTP POST operation. The SHLink Creator returns an SHLink that contains access to the manifest file for accessing the clinical data that was requested.
• Retrieve SHLink Manifest [CA:SHL-2] – This transaction sends a Retrieve SHLink Manifest Request from an SHLink Consumer to an SHLink Responder. The SHLink Responder returns the Manifest file that contains the location of the clinical data that was requested.
• Retrieve SHLink Clinical Data [CA:SHL-3] – This transaction sends a Retrieve SHLink Clinical Data Request from an SHLink Consumer to an SHLink Responder. The SHLink Responder returns the clinical data that was requested with applied encryption. The SHLink Consumer decrypts the data using the key provided in the SHLink.