With the completion in June 2025 of the sequential projects NUM-CODEX and NUM-RDP, important foundations were laid for digital health research in Germany. The projects aimed to merge routine clinical data from university hospitals so it can be used safely, in a standardized form, and in a future-proof way for research and patient care. Both projects were funded within the Network of University Medicine (NUM) and implemented jointly with the Medical Informatics Initiative (MII).
Within the MII, modern, interoperable infrastructure solutions were developed to facilitate the use of medical patient data for research purposes as well as pandemic and crisis preparedness. Building on the data integration centers of the individual hospitals, cross-site technologies were established that improve the availability of high-quality data for research, teaching, and clinical decision-making — thereby helping to optimize patient care in the long term.
During the COVID-19 pandemic, CODEX created a data platform in a very short time that successfully connected all German university hospitals and was further expanded in RDP. This demonstrated for the first time how a generic, harmonized data-use infrastructure with standardized endpoints at all 34 partner sites nationwide can make health data accessible for secondary use with unified procedures and under very high data-protection requirements. The standardized endpoints of the Data Integration Centers (DIZ), the central infrastructure components, and the distributed data extraction process with federated record linkage were developed and rolled out based on the use-case-agnostic open-source infrastructure Data Sharing Framework (https://dsf.dev). NUM RDP thus contributed to making the various data infrastructures from the MII and NUM interoperable. The resulting infrastructure was based on internationally recognized standards such as FHIR (as the national interoperability standard) and openEHR (for central storage). EHRbase, an open-source implementation of the openEHR standard, was further developed for this purpose. In addition to solutions for data storage, methods for integrating the two standards as well as user-oriented tools for selecting and presenting relevant data were provided. All solutions are fully compatible with the standards defined by the MII.
With the NUM Dashboard, a federated analytics infrastructure with central visualization components, originally developed in the early pandemic phase within the MII, was further enhanced (https://numdashboard.ukbonn.de) and, by the end of the project, was regularly supplied with aggregated data extracted directly from routine documentation at 26 university hospitals. Likewise, the federated record linkage concept developed within the MII was implemented for the first time using the federated Trusted Third Party (fTTP) and the NUM Transfer Hub, which were established in practice with all participating university hospitals (https://www.ths-greifswald.de/fttp).
NUM-CODEX and NUM-RDP have not only shown how modern interoperability solutions can be successfully implemented, also built important bridges between existing systems and regulatory frameworks. The experience gained and the technologies developed now form valuable building blocks for future national and European projects and contribute to preparing Germany’s digital health infrastructures for the European Health Data Space (EHDS)