## 4 Gaia-X
### Addressing Conceptual Shortcomings of Gaia-X  
In the following, we present our adaptations of Gaia-X's concepts to enable individual persons not associated with a single organization, such as patients, to participate in federations, while keeping their data sovereignty. In the Gaia-X specifications, individual persons are considered end-users associated with exactly one organization, as customers or employees, while only organizations can be Participants. This conceptual shortcoming has often been addressed by integrating _Personal Data Wallets_, possibly even finding its way into the Gaia-X specifications via a \"Wallet Task Force\" [28]. This would be in accordance with efforts like the Gematik ([[https://www.gematik.de/](https://www.gematik.de/)]([https://www.gematik.de/](https://www.gematik.de/)) (accessed on 5 December 2024)) and electronic health records in Germany (ePA, s. above) and other countries like Denmark ([[https://healthcaredenmark.dk/national-stromholds/digitalisation/digital-infrastructure/](https://healthcaredenmark.dk/national-stromholds/digitalisation/digital-infrastructure/)]([https://healthcaredenmark.dk/national-stromholds/digitalisation/digital-infrastructure/](https://healthcaredenmark.dk/national-stromholds/digitalisation/digital-infrastructure/)) (accessed on 5 December 2024)), or Estonia ([[https://e-estonia.com/solutions/e-health/e-health-records/](https://e-estonia.com/solutions/e-health/e-health-records/)]([https://e-estonia.com/solutions/e-health/e-health-records/](https://e-estonia.com/solutions/e-health/e-health-records/)) (accessed on 5 December 2024)). To explain our approach in addressing this shortcoming, we briefly present and discuss the options we explored. Figure 4 shows the three different options as flows of data. In the very common Figure 4a, a researcher or company obtains patient data stored in hospital or doctor's office information systems, despite patients providing certain medically relevant information only directly, via wearables or questionnaires. Supporting this flow, DICs provide anonymized routine data of multiple patients after ethical approval by the associated hospital of the requester's stated purpose, which has to be for research. Patients enable DICs to do this by compromising on their data sovereignty via a broad consent agreement. For patients unwilling to compromise, the hospitals and doctor's offices effectively engage in consent management, acting as custodians of patient data and asking patients directly before sending any data. Forwarding each data request to all previous patients seems organizationally infeasible, given that contacting patients for  
Figure 4: Diagram showing three different flows (**a–c**) of patient data from hospitals, doctor’s offices, insurance companies, as well as patients themselves, to interested researchers and companies, while keeping the patient in control. routine checkups already poses challenges to many medical professionals. Furthermore, interested researchers or companies will have to contact many institutions to form a coherent dataset, since individual patients can visit many hospitals and doctor's offices, change insurance companies, move cities, etc. Figure 4b aims to remedy these problems by first contacting patients directly and obtaining their authorization to access the relevant, agreed-upon parts of the data they would be able to access at all involved institutions, thus keeping the patient fully in control of the data, even without requiring resources to store the data themselves. We therefore consider this approach as matching Gaia-X very well and advocate for its inclusion. However, when integrated via patients effectively becoming trust anchors and certifying access rights for the requesters, this does not fully solve the problem, since patients themselves can also be a source of data. Lastly, Figure 4c addresses this last point and is the approach we decided to employ. Patients here are regarded as the single source of their data from the point of view of interested researchers and companies.