201801 Direct Track

Return to Jan 2018 Proposals

Direct

FHIR is a new standard that defines a healthcare standards, web API and other related specifications for health data exchange. Direct is an existing federal standard that is widely used in the USA for the exchange of healthcare data. Within the Direct community, Direct Trust provides scalable security and a trust framework through a single Federated Services Agreement, formal policies, accreditation, and a PKI-based trust authority. Because there is such expenditure involved in planning, setting up and maintaining trusted distribution networks, there is strong incentive to leverage existing networks as much as possible. Therefore, this track will explore two possible models of leveraging DirectTrust’s trust framework.

They are:

• Sending FHIR resources within a Direct Message as an attachment
• Utilizing DirectTrust certificates with the FHIR RESTful API to enable trust relationships to scale

Pre-Requisites

For all levels of testing the required pre-requisite is the fundamental requirement that all FHIR servers SHALL support the capabilities interaction.

In addition for track 1, participants will need a Direct implementation that can send / receive direct messages with attachments.

Track Administration

• Coordinator: Luis Maas, EMR Direct - lcmaas at emrdirect dot com
• Coordinator: Calvin Beebe, Mayo Clinic - cbeebe@mayo.edu
• Management & Communications: Dr. David Kibbe - DirectTrust President and CEO - david.kibbe@directtrust.org

Expected participants

• Luis Maas – EMR Direct
• Bruce Schreiber – MaxMD
• Don Jorgenson - Inpriva
• Jim Fisher — MedAllies
• Michael Mall — iShare

Scenarios

The following scenarios will be exercised within the track:

1. Sending FHIR resources within a Direct Message as an attachment
   1. Suggested workflow #1: FHIR bundles as content to be loaded by receiving FHIR server (as per FHIR Connectathon 16)
   2. Suggested workflow #2: standardized message structure to trigger a FHIR query at receiving end and return result
   3. Suggested workflow #3: encapsulated FHIR queries using Context IG
   4. Tasks will be documented after approval of use case - [Lisa/Bruce to detail]
2. Utilizing Direct Trust certificates with the FHIR RESTful API to enable trust relationships to scale
   1. Tasks will be documented after approval of use case

Overview of Scenario 1

1. A simple use case that includes transmitting clinical information via a workflow using FHIR resources. Specifically, state – FHIR Resources (give the names), problem list, medication list, allergies – and transport these as attachments. Grahame has already demonstrated this use case - Sending FHIR resources in Direct Messages.
2. By law every patient has a right to receive their medical record. To support this, Stage 3 of the CMS Meaningful Use program is further expanding how a patient can gain electronic access to their health information. In addition to view/download/transmit through patient portals, the measure can be fulfilled by patients retrieving their record within 24 hours of its availability via ONC-certified API in a third party application.
   1. A patient will query their medical record simply by sending a Direct Message to a Direct Address associated with a FHIR interface. Therefore any hospital or provider organization utilizing a FHIR enabled EHR can meet the MU3 requirement by implementing this solution and providing Direct Addresses to their patients. Consolidation of login credentials from multiple patient portals to a singular Direct Address with a familiar mail interface could help overcome adoption challenges.
   2. TODO: whose responsibility is it to authorize the query? how are the identity assertions carried in the message validated and secured?
   3. Applications for this patient and consumer Direct Messaging extend use cases beyond the new Stage 3 measure. Patient Direct Addresses also open up a secure and scalable channel for chronic disease management, medication reminders, and most importantly it empowers patients to manage their health electronically.

Use Case #1 - Scenario 1

narrative of real world problem - e.g. Physician wanting to transmit lab results about patient to referring physician.

Roles

Source FHIR Server

Source EMR

Target FHIR Server

Target EMR

Steps for Direct Transfer

tdb

Use Case #2 - Scenario 1

narrative of real world problem - e.g. Patient submits a request from their direct address to a provider organization to receive clinical information as FHIR resources.

Roles

Source FHIR Server

Source EMR - Patient Portal

Target FHIR Server

Target EMR

Steps for Direct Transfer

tdb

Relevant Specs, Documentation and Test Servers

• Sending FHIR resources in Direct Messages: Sending FHIR resources in Direct Messages.
• Publicly Available FHIR Servers for testing: Publicly_Available_FHIR_Servers_for_testing
• Open source FHIR Implmentations: Open_Source_FHIR_implementations

Other references Links from previous event: Consumer Centered Data Exchange

Work on Advanced Directives: C-CDA on FHIR

Overview of Scenario 2

The following use cases will be backed by a trusted certificate ecosystem:

A. Mutual TLS client-server authentication/authorization
B. Authentication and Authorization JWTs backed by trusted certificate ecosystem

Preconditions:

• The DirectTrust Interoperability Testing Bundle will be used as the trust bundle to establish trust for the connect-a-thon.
• Each client will obtain or generate suitable certificates chaining to a certificate in this bundle. EMR Direct can provide test certificates to interested parties who do not operate their own CA.
• For Use Cases #A2 and #B1, the AS will grant tokens with full read access to demographic, immunization, and allergy data.

Use Case #A1 – Mutual TLS with FHIR Server (Full Read Access)

1. FHIR client presents a client certificate to Resource Server during SSL handshake in place of a conventional OAuth Bearer Access Token.
2. RS validates certificate using standard PKI processes and determines whether client certificate chains to anchor in DT Interop Testing Bundle.
3. If certificate is invalid or untrusted, the FHIR request is denied.
4. If certificate is valid and trusted, RS allows read access to resources.

Note: For purposes of this use case, successfully authenticated client are authorized for full read access.

Use Case #A2 – Mutual TLS with OAuth Server

1. FHIR client presents a client certificate to Authentication Server token endpoint during SSL handshake in place of a client secret for client_credentials grant workflow.
2. AS validates certificate using standard PKI processes and determines whether client certificate chains to anchor in DT Interop Testing Bundle.
3. If certificate is invalid or untrusted, the request is denied.
4. If certificate is valid and trusted, the AS grants a conventional OAuth Bearer Access Token to client.
5. Client presents access token to RS when making FHIR requests in the usual manner.

Use Case #B1 – Client authentication backed by trusted certificates

1. FHIR client presents signed JWT to AS token endpoint for client_credentials grant workflow, using the client_assertion and client_assertion_type parameters as per UDAP OAuth profile. Note: how the client is registered with the AS is out of scope (e.g. dynamic or manual registration)
2. The AS validates the signature on the JWT, and validates the certificate backing the signature using standard PKI processes and determines whether client certificate chains to anchor in DT Interop Testing Bundle.
3. If signature is invalid, or certificate is invalid or untrusted, the request is denied.
4. If signature is valid, and certificate is valid and trusted, the AS grants a conventional OAuth Bearer Access Token.
5. Client presents access token to RS when making FHIR requests in the usual manner.

Help Links

Here are some links to assist implementers:

TestScript(s)

TBD

Results

FHIR Connectathon 17 will be held on January 27-28, 2018 in New Orleans. A link to download the report will be available after the conclusion of the Connectathon

Governance Questions

This section will identify any governance issues or questions that arise from the Direct Track

References

Direct, DirectTrust, and FHIR: A Value Proposition