Biomedical Research Integrated Domain Group (BRIDG) Model
BRIDG is a domain analysis model that represents the realm of protocol-driven clinical, pre-clinical, translational and basic research. This breadth includes concepts from Common (i.e., concepts shared by all research protocols), Protocol Representation, Study Conduct, Adverse Events, Biospecimen, Molecular Biology, Experiment, Statistical Analysis and Regulatory subdomains. These research concepts provide a shared understanding of biomedical semantics (i.e., what each concept means and how it relates to other concepts) so that these semantics can be easily understood by subject matter experts in the biomedical domain.
Software architects or developers and data managers can use the model to design software systems and databases, respectively, that share the same semantics. This use of BRIDG helps support the meaningful exchange of data between those systems; this approach has been taken by academic, biopharmaceutical, government and regulatory organizations as well as clinical research organizations worldwide. The biomedical semantics of BRIDG are described as:
“The data, organization, resources, rules, and processes involved in the formal assessment of the utility, impact, or other pharmacological, physiological, or psychological effects of a drug, procedure, process, subject characteristic, biologic, cosmetic, food or device on a human, animal, or other subject or substance plus all associated regulatory artifacts required for or derived from this effort, including data specifically associated with post-marketing adverse event reporting.”
BRIDG uses healthcare datatypes as its syntax to frame these semantics in a way that “bridges” CDISC Foundational Standards, research and healthcare concepts, and many organizations. Semantic and syntactic standards are necessary to facilitate software interoperability, where different systems can meaningfully exchange data. When used to design software systems and databases, BRIDG supports interoperability.
BRIDG is a CDISC, HL7 (Healthcare Level 7) and ISO (International Standards Organization) standard. BRIDG 5.0 and prior releases are available to view or download, requiring Enterprise Architect tool, at the model’s website.
Stakeholders and Development
For nearly ten years, CDISC, U.S. National Cancer Institute (NCI), Food and Drug Administration (FDA), HL7 and ISO have been key BRIDG stakeholders. These stakeholders, as well as members of academia, clinical research organizations, information technology teams and others have participated in the ongoing development and maintenance of BRIDG through its Modeling Team, Working Group and Steering Committee.
BRIDG Relationships to Other CDISC Standards
Because BRIDG includes concepts spanning the full spectrum of biomedical and health research, it can be used as a reference tool when creating new standards or adding new content to an existing standard. This referencing ensures the relationships between, and among concepts, in a new or expanding standard, are compliant with an existing model that has been vetted by subject matter experts. BRIDG is often used as a reference tool when developing Foundational Standards, Therapeutic Areas and Biomedical Concepts. Mappings from these standards to BRIDG can be explicitly defined. These bindings, plus several versions of BRIDG, have been imported in the CDISC SHARE metadata repository to make them available electronically.
In addition to reference, many CDISC Foundational Standards are harmonized within BRIDG. The model include mappings to Study Data Tabulation Model Implementation Guide (SDTMIG) and CDASH. The Pharmacogenomics/Genetics Implementation Guide is also harmonized with BRIDG to inform its representation of genomic, proteomic and other related semantics from humans and microorganisms. These mappings to the BRIDG model provide a visual representation of CDISC standards, and help ensure different software systems and databases developed using the model share semantics to meaningfully exchange data. For more details on BRIDG's release history, please visit https://bridgmodel.nci.nih.gov/about-bridg/background.
Recent BRIDG Releases
BRIDG is an actively developed model, where modeling activities are largely performed as part of an HL7 sponsored BRIDG Work Group and guidance and prioritization from a Steering Committee, consisting of representatives from key stakeholders and academia. The download or view releases of BRIDG, navigate to https://bridgmodel.nci.nih.gov/download-model
The BRIDG Steering Committee and BRIDG Stakeholders, including Clinical Data Interchange Standards Consortium (CDISC), U.S. Food and Drug Administration (FDA), Health Level Seven (HL7), International Standards Organization (ISO) and the U.S. National Cancer Institute (NCI) are pleased to announce the BRIDG Modeling Team’s release of version 5.0 of the Biomedical Research Integrated Domain Group (BRIDG) model.
BRIDG 5.0 is available for download at:https://bridgmodel.nci.nih.gov/download-model/bridg-releases/release-5-0
BRIDG 5.0 is a major release for the project. The scope of this release includes new semantics from three different efforts listed below plus some new views of existing semantics.
Imaging Harmonization (including parts of DICOM)
The US National Cancer Institute (NCI) has use cases that need integration and harmonization of semantics between the clinical research domain and the imaging domain. The focus was specifically to harmonize relevant parts of the DICOM standard and an NCI project – Annotation and Image Markup (AIM). DICOM is a widely accepted ISO standard that “addresses the exchange of digital images, and information related to the production and management of those images, between both medical imaging equipment and systems concerned with the management and communication of that information.” NCI’s AIM project has created a standard means of adding information and knowledge to an image in a clinical environment, so that image content can be easily and automatically searched.
The scope of this Imaging harmonization was limited to support the following high level use cases: Identification of entities – person, animal, specimen, imaging study; Image acquisition; Image Type (modalities – CT, MR and PET); Annotation & Structured Reporting.
One of the key aspects of this harmonization of imaging semantics is that the BRIDG modeling team has leveraged the principles of “modeling-by-reference” which essentially means that when an established standard exists in a particular domain (like DICOM for Imaging) then not all the semantics of the referenced standard will be harmonized with BRIDG. Instead the harmonization effort will focus on aligning the common semantics between the two domains to support implementable interoperability use cases. The focus was to identify the touch points between BRIDG and DICOM to support users finding sufficient commonly used, high-level imaging concepts, link the relevant parts to the clinical research context in BRIDG, and thereby allow users to identify which imaging studies to pursue at a more detailed level in DICOM.
A small set of new semantics was added for trial management and monitoring. This harmonization was scoped to tracking resources, countries, and subjects in a Study, etc. One of the significant changes that was made to the BRIDG model due to the requirements brought forward from the vendor was related to change in the way BRIDG models the “identifier” classes and attributes. In past releases, many of the identifier attributes were modeled as separate classes from the class they identified. This separate class was necessary because additional identifier semantics, e.g., type code, were needed to describe the identifier. The II (Instance Identifier) data type did not include the additional semantics. For example, in past releases, the Organization class had an association to the OrganizationIdentifier class. In BRIDG R5, a new data type extension, the ID (Identifier) data type, has been added as a class that can be used as a data type for identifier attributes. This new ID data type includes more properties that many identifier attributes need. As a result of adding this ID data type, eleven identifier classes were deleted since the identifier attribute was moved into the identified class.
NCI’s Surveillance Epidemiology and End Results Reporting (SEER)
The Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute (NCI) is an authoritative source of information on cancer incidence and survival in the United States. The SEER Program registries routinely collect data on patient demographics, primary tumor site, tumor morphology and stage at diagnosis, first course of treatment, and follow-up for vital status. To learn more about SEER program, visit https://seer.cancer.gov/
One of the main aspect of this harmonization was addition of class called “StandardOfCareDataCollection”. This harmonization now allows the BRIDG model to support use cases where clinical data is collected about patients who are not necessarily enrolled on a clinical trial. This has introduced the touch point between clinical data and clinical research data.
One of the constructive criticisms that has been voiced about the BRIDG model is that the model is very large and complex and therefore difficult to review the semantics. This is true when someone looks at the Comprehensive UML model view of the BRIDG model. The intent of that view was purely for maintenance purposes to allow the BRIDG modeling team to ensure the integrity of the model. The Comprehensive View was never intended to be the presentation to read and understand the BRIDG model. The sub-domain views were intended to be that user-friendly and consumable view to read and learn the BRIDG model. Based on the comments received during various ballot cycles, it has become clear that the sub-domain views are also too big. In response to the comments, the BRIDG members have now actively started developing small, consumable views of the BRIDG semantics. These new views are presented in a package called “Additional Focused Views”. Following are the five new views added in release 5.0:
- Oncology View (in support of NCI Oncology semantics and the CDISC Oncology domains/variables)
- SDTM 3.1.3 View
- SDTM Exposure (EX) Domain View
- SDTM Disease Response (RS) View
- SDTM Vital Signs (VS) View
Please visit https://bridgmodel.nci.nih.gov to learn more about the BRIDG Model project.