Changes to the HL7 FHIR standard in FHIR R6 include many items needed to design, conduct, and report clinical trials. These changes lay the groundwork for researchers to use FHIR to communicate and conduct their research.
The FHIR Group reshaped the Resource to support structured eligibility criteria, especially given the potential to accelerate trial recruitment through automated matching. These changes were initially developed in the HL7 Biomedical Research & Regulation (BRR) Work Group. In the May 2026 FHIR Connectathon, supported by both the Vulcan Accelerator and the Evidence Based Medicine on FHIR (EBMonFHIR) project, an AI-powered Clinical Trial Eligibility Criteria Track established key principles and proof-of-concept functionality and impact for using AI (or Super Intelligence as it may be named today) to transform unstructured eligibility criteria from ClinicalTrials.gov to well-structured Group Resources matching the StudyEligibilityCriteria Profile from the EBMonFHIR Implementation Guide.
The work continues in an open working group meeting (AI-structured Eligibility Criteria Working Group) on Mondays at 11 am Eastern time (https://fevir.net/HEvKA) and has been featured in the CMS Health Technology Ecosystem Clinical Trial Matching track.
The FHIR ResearchStudy Resource was reshaped to specify comparison groups with the same level of detail as the study enrollment group, thus enabling systems capable of automated matching to assign study participants to comparison groups.
The FHIR ResearchStudy Resource was reshaped to fully specify outcome measures, including the estimand framework and endpoint analysis plans, meeting new expectations from regulators with the ICH E9 (R1) addendum on estimands and sensitivity analysis in clinical trials and the guideline on statistical principles for clinical trials.
The FHIR Extensions Pack includes ResearchStudy-specific extensions for site recruitment, investigator recruitment, and interventionalist recruitment to address the many recruitment efforts needed beyond participant recruitment for conducting many research studies, as well as blinded-role, where classifications such as ādouble-blindā and ātriple-blindā are insufficient to understand who was blinded in a given study.
The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) is a global nonprofit organization that unites regulatory authorities and pharmaceutical companies. When ICH developed its M11 technical specification for the Clinical Electronic Structured Harmonized Protocol (CeSHarP), it sought HL7’s support in developing a technical implementation guide. The HL7 Vulcan FHIR Accelerator stepped up to meet this need within their Utilizing the Digital Protocol (UDP) project and created the Clinical Study Protocol Implementation Guide (https://build.fhir.org/ig/HL7/vulcan-udp-ig/en/). This āVulcan UDP IGā includes all the structures to support CeSHarP in FHIR-based data exchange.
ClinicalTrials.gov, the most prominent and largest research study and clinical trial registry in the world, added a FHIR export in its modernization efforts in 2002. The underlying API service has been continually adapted to produce FHIR-structured results using the latest version in the FHIR R6 continuous build, and was last updated September 30, 2026.
After demonstrating scaled conversion of ClinicalTrials.gov study records to FHIR, the European Medicines Agency (EMA) expressed interest in exploring a proof of concept to map selected data elements from the European Union (EU) Clinical Trial Information System (CTIS) public portal to FHIR. This initiative led to the development of a StudyRegistryRecord Profile within the EBMonFHIR Implementation Guide. A proof-of-concept prototype converter from EU CTIS to FHIR, which transforms EU CTIS public portal data into FHIR, was subsequently developed and successfully evaluated in multiple Evidence-Based Medicine Tracks at FHIR Connectathons, as well as within the EMA.
The work continues in an open working group meeting (StudyRegistryRecord Working Group) which meets every Wednesday at 11 am Eastern time (https://fevir.net/HEvKA).
Brian Alper, MD, MSPH, FAAFP, FAMIA, FGIN
Co-Chair, HL7 BRR Work Group; Lead, EBMonFHIR Project; CEO, Computable Publishing LLC; President, Scientific Knowledge Accelerator Foundation; Chair, Guidelines International Network Technology Work Group