Unified Study Definition Model (USDM) Class DiagramThe USDM Class Diagram is a UML class diagram that functions as the Study Definitions logical data model (LDM). The class diagram as LDM depicts the classes and attributes that represent data entities and the relationships between those entities needed to support a conformant Study Definitions application. The class diagram includes a data dictionary that defines each of the classes and attributes to provide the semantics needed to implement the model consistently. The purpose of the LDM is to provide a normative standard to the solution implementer in order for them to create and implement a physical model. The LDM does not attempt to be inclusive of every class, attribute, and relationship implemented by any given solution. Instead, the LDM describes all elements for a conformant solution based on Release 1 and 2. It provides input into the solution architecture with the expectation that every effort will be made to ensure the solution architecture aligns with the RA LDM. The LDM represented by the class diagram may be implemented in a variety of physical data stores, including relational databases, property graph databases, RDF triple stores, document databases, and others. The semantics represented in the LDM and its data dictionary support a uniform understanding of the Study Definition data elements to improve interoperability. The LDM will be used to define the resources available in the API specification, and these resource definitions represent the data exchange format for applications implementing the API. The class diagram references both CDISC and non-CDISC industry standards and terminology systems where relevant. It will be developed for compatibility with all other existing CDISC Standards that model protocol concepts, to ensure consistent terminology and relationships are used in USDM. Where the class diagram references external standards, CDISC will document these connections in order to help explain to the user community the provenance of the links. For example, the Study Definition class diagram includes references to new CDISC Biomedical Concepts, CDISC foundational standards, as well as CDISC controlled terminology. The data dictionary built into the class diagram will include references to the CDISC Library for retrieval of all CDISC content. Content from other standards and terminology systems will be incorporated where appropriate into the LDM, such as HL7, LOINC, Common Protocol Template, ICH M11, and others, either directly or through external linking, with the intention of extending interoperability in the future to data exchange standards such as HL7 FHIR. The class diagram also depicts essential elements of a study protocol including but not limited to study objectives, endpoints, and the schedule of activities (SoA). |