Overview HL7® FHIR® and Bulk FHIR

Dan Gottlieb (Boston Children’s Hospital & Harvard Medical School)


FHIR is emerging as the rally point for data standards—and for good reason. It offers data building blocks that can be combined to ensure health data can be more easily analyzed, interpreted, and put to use. Release 2 is being used in production today, and release 4 is increasingly moving toward adoption. Bulk FHIR allows data to flow in batches at a population level, and it is already supported by entities like CMS, Microsoft, and IBM. Increased adoption of FHIR-based approaches could help public health to access and share information more broadly and seamlessly.

Key Takeaways

FHIR is Emerging as a Lingua Franca to Promote Interoperability

FHIR provides a set of data models—called resources—that can be queried in different ways and linked together. It’s helpful to think of these resources as chunks of health information clumped together into building blocks, such as patient demographics, medications, immunizations, or claims, that can be combined to answer both simple and complex questions about healthcare.

FHIR resources mature at different rates, depending on testing and adoption. At set points in time, the standard “stands still” and is versioned. FHIR release 2 is the main version that is in production now and is being used by Apple among many other implementers. In building toward the future, EHR vendors are required to support FHIR release 4 to fulfill regulatory requirements for health IT certification.

Bulk FHIR Makes it Easier to Access Data on Groups, Cohorts, and Populations

Bulk FHIR is designed to exchange large analytical datasets. It is a batch API, wherein data may be queried nightly or on another regular basis to pull data (in a streaming way) into a platform that will be used for analytics. It allows data requestors to access data from multiple EHRs in a standardized and secure way without manual processes and without having to customize routines for every vendor or every site. Bulk FHIR also supports updates so if, for example, you do a nightly data pull, you can request only data that have changed since your last pull.

Microsoft, IBM, and other technology vendors support the bulk FHIR API already. CMS is using it   to send beneficiaries’ claims data to healthcare providers and accountable care organizations to help improve health outcomes and lower costs. Additionally, EHR vendors are starting to prepare to support this capability in anticipation of the federal regulations going into full effect in 2022.

Core Data Elements for Interoperability will be Mapped to the FHIR Standard and Supported Nationwide

Today, the common clinical data set provides a baseline for what health information can be easily exchanged. Moving forward, USCDI will become the new baseline. It includes clinical notes and additional data elements, such as lab results, problems, procedures, vital signs, data provenance, and more detailed demographics. USCDI will grow and evolve over time based on a processexternal icon defined by ONC. Public health officials are encouraged to recommend changes and additions to USCDI following the ONC-defined process. A draft of the next version of USCDI will be presented to the public for review and comment before it is finalized.

Modern Technologies that Underpin FHIR are not Specific to Healthcare, Making FHIR a Powerful Engine for Growth and Innovation

FHIR is an open standard, licensed under creative commons. You don’t have to subscribe or pay any fees to access or use it, unlike other standards where you have to become a member before you can even read the documentation. The standard uses the same underlying set of web-based protocols modern developers use at companies such as Amazon, Twitter, and other tech companies. This makes FHIR-based solutions compatible with modern technologies and advanced analytical approaches.