History of BRIDG

2003-2004: CDISC initiates a domain analysis modeling project

The initial domain analysis model emerged from a September, 2003 dialogue between the Board of Directors (BoD) of the Clinical Data Interchange Standards Consortium (CDISC) and one of the current members of the BRIDG Technical Harmonization Committee (CM) , then a member of the HL7 BoD. The dialogue itself was in response to a request from CDISC leadership to HL7 leadership that the two organizations renew a then 2-year-old Memorandum of Understanding to work collaboratively on data exchange standards in domains deemed to be of interest to both organizations. CDISC specifically requested an educational session that would assist the CDISC BoD with coming to a better understanding of HL7’s model-based approach to message specification, a process that CDISC had attempted to embrace in the context of the HL7 Regulated Clinical Research Information Management (RCRIM) Technical Committee with somewhat limited success.



The BRIDG model is a DAM and therefore presents only the implementation-independent semantics of a domain-of-interest.             The HL7 Reference Information Model (RIM) and its derived, domain-specific artifacts are, strictly speaking, implementation-independent.             However, they are not “domain-friendly” because the semantics are represented using cross-domain, often-design-level abstractions that are unfamiliar to domain experts. Finally, XML is a particular implementation representation. Representation of the semantics of a domain-of-interest in a separate model from the design or implementation models of those semantics facilitates automated transformations between the various implementations, e.g. between CDISC XML and HL7 XML.


Following discussion, the CDISC BoD elected to begin funding the development of a CDISC DAM, a process that officially started with a scope definition meeting in March, 2004.


2004-2005: The caBIG Structured Protocol Representation (caSPR)


In February 2004, The National Cancer Institute began a similar project to develop a structured model of a clinical trial protocol as part of the caBIG (cancer Biomedical Informatics Grid). Awarded to the University of Pittsburghand funded through the caBIG project, the project was intended to identify a set of data elements suitable for a structured protocol representation. Rather than create “yet another standard” the caSPR project began to collaborate with other groups interested in standardizing the exchange of information related to clinical trials research Working closely with the NCI leadership, both HL7 and CDISC were identified as “best of breed” in the modeling effort in large part because of the work in developing a CDISC DAM.


2005-2006: Maturation of the BRIDG Project:

In the fall of 2004, the first joint modeling session was held between members of the CDISC DAM team and the NCI caSPR teams, and over the next 9 months, this group developed the initial analysis model.


In the summer of 2005, the project was renamed the BRIDG project (Biomedical Research Integrated Domain Group), to represent the “bridges” that we being built between the stakeholder organizations and the model to the BRIDG model to unify the name of the CDISC DAM/HL7 DAM/NCI caSPR models.


The organization of the BRIDG project was modeled on other open source, collaborative software development projects such as Linux, Firefox, and Mozilla. In the spring of 2005, the modeling effort was moved to the software application Enterprise Architect” to support low-cost UML modeling and to allow the dissemination of the model using a free model reader (www.Sparxsystems.com)                           This choice was made based on a comprehensive UML Tool Requirements Analysis done by the NCI, and was influenced in large part by the availability of a free, downloadable EA reader (similar in concept to Adobe Acrobat Reader), which allows anyone interested in the BRIDG model to immediately view – but not edit – the BRIDG model in its entirety. Additional collaborative infrastructure was developed using GForge to maintain documents, bug tracking and version control using source control software subversion.


After the initial model was constructed and presented to HL7, the RCRIM Technical Committee (TC) made an official commitment to use the BRIDG model as its Domain Analysis Model in support of the Requirements Specification portion of the HL7 Development Framework (HDF). This commitment meant that not only would the RCRIM TC use the BRIDG model going forward for all of its message specification efforts, but that it would also reverse engineer all of the implementation-independent semantics from existing RCRIM TC specifications (e.g. Regulated Product Submission, Structured Product Labeling, etc.) into the BRIDG Model.


In the Summer 2005, it became clear that additional strategic oversight was needed within the BRIDG project. The BRIDG advisory Board was created in August 2005 with representation from the FDA, CDISC, NCI, caBIG, and the Pharmaceutical industry. The BRIDG advisory board was charged with identifying and allocating resources to support the modeling effort, establishing priorities for modeling and harmonization efforts, and vetting and reviewing the model within their stakeholder organizations.


Similar to other open source projects, a “Technical Harmonization Committee” or THC was established to manage the operational details of the model construction, harmonization, and dissemination. The THC was intended to support the harmonization efforts of models that were developed. This small team of individuals has representation from standards organizations, the NCI, and academic.

Steve Bridge

University Researcher at On Leave
I'm a researcher specialising in microbiological data analysis, including the natural ecosystem influences and changes over time.

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