FHIR at Scale Taskforce Publishes First Implementation Guides

Dec. 13, 2022
FAST’s role is to identify and foster common scalability approaches to support real-world use cases for HL7 FHIR across multiple domains

The FHIR at Scale Taskforce (FAST), which transitioned from an initiative of the Office of the National Coordinator for Health IT to an HL7 FHIR Accelerator in early 2022, announced the publication of its first two implementation guides (IGs).

FAST works with the HL7 FHIR community to identify scalability gaps and support the development of necessary infrastructure for actionable solutions. Its members include technology companies, health systems, payers, and government agencies. 

“FAST is proud to be a part of the vibrant FHIR ecosystem to support the development and implementation of much-needed data standards,” said Duncan Weatherston, CEO of Smile Digital Health and co-chair of FAST’s Steering Committee, in a statement. “Our role is to identify and foster common scalability approaches to support the real-world use cases for HL7 FHIR across multiple domains. We are thrilled to further the work of our colleagues and publish these initial IGs around security and intermediary data exchange.” 

When FAST was transitioning from ONC to HL7 in April 2022, Micky Tripathi, Ph.D., national coordinator for health information technology, issued a statement saying “Along with the Sequoia Project, we recently published a FHIR Roadmap as part of the implementation of the Trusted Exchange Framework and Common Agreement (TEFCA). FHIR Accelerators like FAST are poised to play a key role in advancing technical specifications that can be implemented at scale within TEFCA and we look forward to what’s to come.”

The first IG, Scalable Security for Registration, Authentication, and Authorization (STU 1), describes how to extend OAuth 2.0 using Unified Data Access Profiles (UDAP) workflows for both consumer-facing apps that implement the authorization code flow and for business-to-business (B2B) apps that implement the client credentials flow or authorization code flow. 

The guide covers topics including automating the client application registration process and increasing security using asymmetric cryptographic keys bound to digital certificates to authenticate ecosystem participants. It also provides grammar for communicating metadata critical to healthcare information exchange. 

The work stems from recommendations of ONC’s FAST Security Tiger Team and has been adapted from IGs previously published by UDAP.org. The objective of the document is to harmonize workflows for both consumer-facing and B2B applications to facilitate cross-organizational and cross-network interoperability. 

The second IG, Hybrid/Intermediary Exchange (STU 1), recognizes that the healthcare ecosystem is a complex one that includes many diverse types of actors including providers, health plans, government agencies, analytics and research, public health, and many others. This ecosystem historically and currently includes intermediaries, such as clearinghouses and health information exchanges (HIE), which broker communication and provide additional value-add services for those actors who choose to use them. This guide addresses the process of integrating intermediary entities into the HL7 FHIR-enabled data exchange environment.   

This guide also provides guidance for enabling HL7 FHIR REST interactions across one or more intermediaries using a passive approach, in which the intermediary acts as a “pass through” (e.g., clearinghouses and HIEs), and the requesting actor is not necessarily aware that the request will be routed through an intermediary entity. 

Potential applications of this initial IG include the Da Vinci value-based care use case, in which intermediaries may bridge connectivity between actors. Other HL7 FHIR accelerators (CARIN, Gravity, etc.) are also developing use cases in which intermediaries may be involved. 

National healthcare directory

FAST also continues to work on other projects, such as three CMS-supported guides describing the technical architecture considerations related a national healthcare directory.   

These guides address challenges including the exchange, query, and attestation and verification of data elements required for a centralized, validated directory system. CMS has also recently released an RFI to collect feedback from the industry on the best approach to developing such a system. FAST will be leading a coordinated team to develop a collaborative response to this RFI.