COMFORTage provides comments on the HealthData@EU Implementing Act
This article summarises the consolidated COMFORTage consortium input on the draft Commission Implementing Regulation on HealthData@EU under Regulation (EU) 2025/327.
Imagine a researcher in Belgium investigating the early signs of frailty, a team in Poland studying dementia risk, or a European research consortium exploring how lifestyle, clinical history and environmental factors influence healthy ageing.
Their work could benefit enormously from access to relevant health data collected across Europe. Yet health information is often scattered across different systems, described using different standards and governed by different rules.
How can we make these data easier to discover and use for research, while protecting people’s privacy and maintaining trust?
This is one of the central ambitions of the European Health Data Space (EHDS), a European initiative designed to improve access to and exchange of electronic health data for healthcare and research.
Within this framework, HealthData@EU is intended to support the secondary use of health data — meaning the use of data for purposes such as research, innovation, policymaking and public health.
The COMFORTage consortium has contributed its perspective to the European Commission’s draft Implementing Regulation on the technical framework for HealthData@EU. Its consolidated input highlights an important principle: building a European health data space is not simply about connecting databases. It is about creating the conditions for data to be securely discovered, meaningfully combined and responsibly used.
Connecting Europe without necessarily moving all the data
One of the key messages from COMFORTage is that European health data interoperability should not automatically mean centralising datasets in one location.
Many health datasets are sensitive, and transferring them may be technically, legally or organisationally difficult.
Instead, the consortium calls for explicit support for federated data processing: an approach in which data can remain within the infrastructure of the organisation holding them, while approved algorithms or analyses are brought to the data. Only authorised results or outputs are then shared.
This approach could be particularly relevant for research involving multiple countries, sensitive health information or large and heterogeneous datasets.
For example, researchers studying dementia and frailty could potentially analyse information held by different participating organisations without requiring all underlying patient-level data to be physically transferred to a central repository.
Such approaches require coordinated security, governance, traceability and compliance mechanisms. But they offer an important architectural option for European research infrastructures.
Interoperability means more than speaking the same technical language
Connecting systems is one challenge. Ensuring that they understand each other is another.
Health information is represented in different ways. Clinical systems may use standards such as HL7 FHIR, while research and analytical environments may rely on models such as OMOP CDM or national data structures.
Converting information between these models is not simply a technical exercise.
A diagnosis, laboratory result or clinical measurement must retain its meaning when transformed. Its coding system, units, timing, context and origin must remain understandable.
COMFORTage therefore calls for technical guidance that supports interoperability between operational clinical data and analytical research models, while preserving semantic meaning and data provenance.
In practical terms, a researcher should be able to understand not only what a data element represents, but also where it came from and how it was transformed.
This is essential for reliable research and increasingly important for advanced analytics and artificial intelligence.
Discoverable data are not necessarily good-quality data
A common European framework for describing datasets is a major step forward.
HealthDCAT-AP, established as the metadata framework for minimum dataset descriptions under a separate EHDS implementing regulation, provides a common structure to help people discover and understand available datasets.
However, knowing what a dataset contains is not the same as knowing whether its contents are accurate or suitable for a particular research purpose.
A dataset may have perfectly compliant metadata while still containing obsolete codes, inconsistent units, incorrect terminology mappings or incomplete clinical information.
This distinction is especially important when data are used to train or validate AI systems.
COMFORTage therefore recommends that the HealthData@EU technical documentation distinguish between:
- Metadata quality: whether a dataset is properly described and discoverable.
- Content quality: whether the actual data are complete, consistent, correctly coded and semantically meaningful.
The consortium also highlights the potential role of reusable validation tools and terminology services to support this second dimension.
For researchers, this means that data quality should be assessed rather than assumed.
Trust must be built into the infrastructure
People need confidence that their health information will be handled responsibly.
For COMFORTage, trust is not just a matter of legal compliance. It also depends on how the infrastructure works in practice.
The consortium highlights several areas requiring clear technical requirements: Reliable identification and authentication of participating organisations and authorised users, access controls linked to roles and permitted purposes, traceable records of data access and exchanges, protection of audit logs and personal information, technical enforcement of the conditions attached to data access permits and clear information for citizens about safeguards against prohibited uses.
These elements should work consistently across national infrastructures rather than relying on incompatible local arrangements.
The objective is to combine accountability and transparency with strong data protection.
One European Health Data Space, not a collection of technical silos
The EHDS is developing through several complementary components.
MyHealth@EU supports cross-border exchange for primary healthcare purposes, while HealthData@EU addresses secondary use for research, innovation and other authorised purposes.
Although their objectives differ, both need to address common challenges involving identity, security, interoperability, terminology and compliance.
COMFORTage therefore calls for coherence between their technical specifications, allowing common components and approaches to be reused wherever appropriate.
The consortium also highlights the importance of alignment with the dedicated EHDS framework for secure processing environments.
This matters because European countries and organisations have already invested in data infrastructures. Building on existing compliant components, rather than unnecessarily duplicating them, could reduce implementation costs and complexity.
Helping organisations make the transition
A European framework can only succeed if organisations have the practical means to implement it.
Many health data holders manage information collected over decades, using different formats, metadata structures and legacy systems. Bringing these datasets into alignment with HealthDCAT-AP will require time, expertise and appropriate tools.
COMFORTage therefore advocates reusable resources such as metadata templates, data dictionaries, mapping tools, automated validation and practical implementation guidance. Particular attention should be given to smaller organisations with limited technical and data-management capacity.
The consortium also highlights the value of accessible legal and technical implementation frameworks to reduce the burden of joining the European data ecosystem.
Preparing for the next generation of health research
Health research is increasingly moving beyond traditional clinical records: Genomics, epigenetics, Wearables, mobile applications, connected medical devices, smart-home technologies and environmental sensors are generating new types of information relevant to health and wellbeing. For research into ageing, frailty and dementia, this diversity is particularly relevant.
Understanding healthy ageing may require combining clinical information with biomarkers, cognitive assessments, lifestyle, environmental factors and patient-generated data.
COMFORTage therefore encourages an extensible HealthData@EU architecture capable of accommodating emerging data types and supporting research across different data spaces.
The consortium also highlights the importance of provenance, reproducibility and traceability when data are used for AI and advanced analytics, while respecting the requirements established under other European legislation, including the AI Act.
The COMFORTage contribution reflects a broader lesson from the project’s work on digital technologies for frailty and dementia prevention: the value of health data depends not only on their availability, but also on their quality, interoperability, governance and responsible use.
A well-functioning European health data ecosystem could help researchers explore questions that cannot be adequately addressed using isolated datasets, support the development and evaluation of digital health innovations, and strengthen the evidence base for prevention and personalised approaches to healthy ageing.
Read the full PDF document to explore COMFORTage’s comments on the HealthData@EU Implementing Act: https://zenodo.org/records/23388187
**Article written by Luc Nicolas from EHTEL (the European Health Telematics Association), a key partner in the COMFORTage project.