Technical Document on Preliminary Common Data Model

The second report of Work Package 5 completes the discussion of the preliminary back-end design concepts of the common data model. The approach of the report is characterized by the principle of least intrusiveness. The proposed solutions respect national idiosyncrasies and allow national centers to advance in a collaborative but independent manner. The report starts by reviewing the data formats of the countries of the consortium. It draws from identification theory and proposes appropriate principles and requirements for the common model's identification design. It examines the functional and informational requirements for identifying various data items and for linking historical data from within the consortium to external databases with contemporary data. It outlines that the common model's implementation mostly benefits from employing both relational and non-relational technologies to address different issues. It highlights appropriate, subsequent steps for cross-country harmonization, firm-linking, data transformation processes, and data governance.