Below is the BRIDG Project timeline that explains the evolution of the project since its inception.

2003—2004: CDISC and HL7 RCRIM WG

The idea of building a Domain Analysis Model (DAM) which documented the shared semantics of the protocol-driven-research domain began with a 2003 dialogue between the CDISC Board of Directors, Charlie Mead, and HL7 leadership. The two organizations renewed a Memorandum of Understanding (MoU) to work collaboratively on data exchange standards. Following discussions, the CDISC Board of Directors began funding the development of a CDISC DAM. The process officially started with a scope definition meeting in 2004, with the resulting DAM ultimately becoming the BRIDG Model approximately one year later. The current scope definition of the BRIDG domain still encompasses what was defined at this initial meeting, i.e. protocol-driven research plus its associated regulatory artifacts.

2004—2005: The NCI caBIG® (and CDISC) Structured Protocol Representation Teams

In 2004, US National Cancer Institute (NCI) began to develop a structured model of a clinical trial protocol as part of the caBIG® project, awarding a grant to the University of Pittsburgh Medical Center to focus on identifying a set of data elements suitable for a computational representation. The NCI team sought out other groups interested in standardizing the exchange of information related to clinical trials research and began collaborating with CDISC and the HL7 RCRIM Work Group. The first joint modeling sessions were held in late 2004 and continued over the next 9 months. This is when the project officially adopted the name "BRIDG" (Biomedical Research Integrated Domain Group), a name chosen more for the meaning of the acronym (to draw attention to the bridging of the semantic gaps that normally impede semantic interoperability) than the collective meaning of the words behind it. This initial effort resulted in the first Domain Analysis Model of protocol-driven research, which at that time was referred to as the "CDISC Problem Space Model."

2005—2006: Maturation of the BRIDG Project

With the inclusion of multiple stakeholders, the need for more formal governance structure became apparent. As a result, the BRIDG Board of Directors (BoD) was created in 2005 with representation from each of the four BRIDG Project stakeholder organizations, i.e. HL7, NCI, CDISC, and the FDA. The BoD was charged with allocating resources to support the modeling effort, establishing priorities for harmonization, and managing the vetting and review of the evolving model within their stakeholder organizations.

It was also decided that a "Technical Harmonization Committee" (THC, later called the "Semantic Coordination Committee" (SCC) and now BRIDG Modeling Team) was needed to manage the operational details of the model construction, harmonization, maintenance, and dissemination. The SCC's responsibilities were defined as making representational changes in the model and ensuring that ambiguous semantics across the various projects contributing to the model were either normalized (different terms for the same concept mapped to that concept) or harmonized (same term for different concepts disambiguated through the creation of new concepts). Like the BoD, the SCC had representatives from the four stakeholders.

Also in 2005, the model was ported from Rational Rose to Sparx Systems Enterprise Architect (EA) tool. This was partly for the lower cost and partly because of the free model reader available from Sparx Systems, the makers of EA ( In addition, the model itself was moved from residence on a single laptop to a GForge site.

An early version of the BRIDG Model was presented to the HL7 RCRIM WG in late-2005/early-2006 and was subsequently adopted as the Domain Analysis Model for use by the HL7 RCRIM WG in compliance with the HL7 Development Framework (HDF) and its increased focus on robust representation of implementation-independent requirements. The intention was that the HL7 RCRIM WG and CDISC would use the BRIDG Model going forward for all message or technical specification efforts and reverse engineer all of the implementation-independent semantics from existing RCRIM & CDISC specifications into the BRIDG Model. As it turned out, some specifications were harmonized with BRIDG (e.g. HL7 Regulated Product Submission, CDISC SDTM), but not all.

2007 - 2012: BRIDG Evolution

BRIDG became more visible in the community, the SCC started hearing feedback from both domain experts and technologists. Many domain experts said that the model was too large, too technical, and did not represent their semantics in language they could understand. The technologists said that the model was not clear enough to map cleanly to downstream models (e.g., design models, implementation models, etc.). As a result, the BoD and SCC designed a BRIDG solution that would present each audience with its own perspective on the semantics of protocol-driven research tailored for their purposes: the UML model was intended for use by domain experts, analysts and some implementers; the HL7 RIM-based model was intended for use by HL7 v3 message developers; and the OWL-based version was intended for use by ontologists for semantic validation and inferencing. Over time, the RIM- and OWL-based versions garnered less interest than initially anticipated, especially given the additional effort required, and were eventually omitted from the later releases.

In late 2008, the BoD decided to move BRIDG forward as an international standard through the ISO, which assigned the identifier “14199” to BRIDG, and Technical Committee (TC) 215 approved the recommendation to circulate BRIDG as a Draft International Standard (DIS) ballot. During the summer of 2010, the 254 comments from that ISO Joint Initiative Council (JIC) ballot cycle (along with a parallel comment period within CDISC and a ballot within HL7) were processed and included in the next two releases of BRIDG.

There were multiple BRIDG releases during this time period, each including new semantics from the various stakeholders models. To see the entire list of BRIDG releases and the projects that were harmonized, please go to Download & Archive > Download Release Packages & Browse Online on this website.

2013 – 2016: BRIDG Scope Expansion – Translational Research

Following a gap in the BRIDG project in late 2012 to early 2013, during which the BoD was reorganized into the BRIDG Advisory Panel, the leadership of BRIDG determined that an NCI model called the Life Sciences Domain Analysis Model (LS DAM), a peer of BRIDG that had leveraged common concepts already defined in BRIDG, should be harmonized with BRIDG. The scope of the resulting model would then be “basic, pre-clinical, clinical, and translational research and associated regulatory artifacts”. This process started in 2013 and completed in 2015 (with another gap in the project from late 2013 to mid-2014). The LS DAM harmonization introduced 3 new sub-domains covering concepts related to biospecimens, molecular biology and experiments.

In 2014, a new work group called the HL7 BRIDG Work Group was started. This group provided a platform for BRIDG users and implementers to discuss BRIDG and identify areas of enhancement. That same year, the Advisory Panel was reorganized into the BRIDG Steering Committee which governs the development and maintenance of the model performed by the SCC as it was called then, and the BRIDG Modeling Team as it is now.

Subsequently, in early 2015, the CDISC Pharmacogenetic and Pharmacogenomic (PGx) domains were harmonized with BRIDG to complement the related genetic/genomic concepts added to the model for LS DAM. The PGx concepts leveraged and helped flesh out some concepts identified earlier by the LS DAM harmonization.

BRIDG 4.0 was balloted in May 2015 in the HL7 community as a Draft Standard for Trial Use (DSTU) with ballot comments coming from the FDA and clinical genomics communities and resulted in model changes, documentation updates and a new architectural focus on making BRIDG more SME-friendly.

2017 – Present: Imaging, SDTM and Model Stability

In 2017, the HL7 BRIDG Work Group was re-merged with the RCRIM Work Group under the new name Biomedical Research and Regulation (BR&R) Work Group. The BRIDG modeling team continues to vet proposed changes to the model with the BR&R Work Group which still uses BRIDG as its Domain Information Model.

In recent years, the BRIDG model has added a new Imaging sub-domain and harmonized a number of standards brought by NCI to address the integration of the clinical research domain with imaging concepts which in the past have often been disconnected. An assortment of imaging-related projects have been harmonized with BRIDG including relevant parts of the DICOM standard pertaining to the breast cancer standard report (SR TID 1500), the NCI’s Annotated Imaging Markup (AIM) project, the National Biomedical Imaging Archive, and IHE’s Anatomic Pathology Structure Report. BRIDG is not intending to absorb all of DICOM detailed level concepts, but just the portions that are overlapping with the clinical research sphere and the high level imaging parameters that researchers would want to use as search criteria to identify imaging data relevant to their research.

Notably, recent harmonizations have not added large numbers of concepts to the model, thus demonstrating its relative stability and coverage of core clinical and translational research concepts. This is seen in the harmonization of CDISC’s SDTM IG v3.2, which introduced approximately a dozen new domains and updates to several existing domains, but didn’t add substantially to the BRIDG model. Also harmonized during this time was the FDA’s Common Data Model Harmonization (CDMH), which was based on the harmonization of 4 key models: Sentinel v6.0.2, PCORnet v4.0 (and v3.1), i2b2ACTv1.7.08b, and OMOPv5.2. The purpose of this project is to provide researchers patient-centered outcomes data by leveraging the four existing systems and using BRIDG as the intermediary model in which to form a query that could be translated into the various formats of the data partners. Interestingly, CDMH harmonization also didn’t add many semantics to the BRIDG model.

Another aspect of BRIDG that has been evolving recently is the subsetting of groups of concepts into smaller diagrams and associated metadata reports, all with the intent of making it easier to find and understand the range of concepts in BRIDG. These can be found in the Additional Focused Views and CDISC Views packages.