The European Health Data Space: How EU Health Data Could Rewrite Evidence-Based Care
A quiet revolution in European health data
As Brussels debates Joint Clinical Assessments (JCAs) under the EU Health Technology Assessment Regulation, a quieter but potentially more transformative reform is advancing in parallel.
The European Health Data Space (EHDS) is not simply another digital health initiative. It represents a structural attempt to redesign how healthcare evidence is generated, shared and used across Europe from regulatory science and health technology assessment to routine reimbursement decisions.
If successful, the EHDS could transform Europe from a landscape of fragmented national health data systems into a continental evidence infrastructure, capable of supporting real-world research, innovation, and more adaptive reimbursement policies.
From scattered records to a shared evidence backbone
Every day Europe’s health systems generate vast volumes of information: electronic health records, disease registries, laboratory results, imaging data, genomic sequences and insurance claims.
Yet most of these datasets remain fragmented across national systems, stored in incompatible formats and governed by different legal frameworks. As a result, the enormous potential of European health data remains largely untapped.
The EHDS seeks to address this fragmentation by establishing a common legal, governance and technical framework for health data interoperability and reuse across the European Union.
Within the EHDS architecture, health data are organised around two principal forms of use.
Primary use
Primary use refers to data used directly in patient care. Under the EHDS framework, citizens will be able to access and share their electronic health records when they move, work or travel across EU Member States.
Secondary use
Secondary use refers to the reuse of anonymised health data for purposes such as research, regulatory evaluation, public health policy and health technology assessment.
It is this secondary use layer that gives the EHDS its transformative potential. National Health Data Access Bodies (HDABs) will function as trusted intermediaries, granting secure access to anonymised datasets for approved research and policy projects.
For the first time, this creates the foundations of a structured European system for large-scale health data analysis.
Real-world evidence at continental scale
Randomised controlled trials remain the gold standard for demonstrating the safety and efficacy of medical technologies. However, they typically involve selective patient populations, controlled clinical environments and limited follow-up periods.
Real-world evidence (RWE), derived from routine clinical data, provides complementary insights into how therapies perform in everyday healthcare settings.
Across regulatory science and health technology assessment, the role of RWE has steadily expanded. The EHDS is designed to accelerate this shift by enabling observational research across multiple Member States simultaneously.
At sufficient scale, such an infrastructure could enable a model of continuous evidence generation, in which the clinical value of medicines and devices is reassessed throughout their lifecycle rather than evaluated only once at launch.
This would represent a significant evolution in how evidence informs healthcare decision-making.
DARWIN EU: the prototype network already in operation
The concept of pan-European real-world evidence is not purely theoretical.
The Data Analysis and Real World Interrogation Network (DARWIN EU), coordinated by the European Medicines Agency, already operates as a federated research network linking hospital data, electronic health records, claims databases and registries across Europe.
Within its first years of operation, the network has grown rapidly.
By its third year DARWIN EU included:
- approximately 30–40 data partners across 16–18 countries
- datasets covering roughly 180–280 million patients
- more than 100 real-world evidence studies, many completed within four months
These studies have already informed regulatory decision-making.
For example:
- A pharmacovigilance analysis of doxycycline use in acne found no increased risk of suicidality, helping the EMA’s Pharmacovigilance Risk Assessment Committee assess a safety signal.
- Drug utilisation studies have tracked changing patterns of ADHD medication prescribing across Europe, supporting regulatory monitoring of prescribing trends.
Technically, DARWIN EU operates using a federated data model: patient data remain in national databases, analyses are conducted locally using shared protocols, and only aggregated results are transmitted centrally.
The EHDS builds upon this model, aiming to extend federated data networks across the wider European health ecosystem.
Early EHDS pilots: testing the concept
Several pilot projects have already explored how EHDS-style cross-border data access could function in practice.
The HealthData@EU pilot programme has tested key EHDS concepts including cross-border data discovery, governance frameworks and secure access mechanisms.
Examples include:
- distributed analyses of coagulopathy-related complications in COVID-19 patients using multinational health datasets
- exploratory studies assessing whether antimicrobial resistance surveillance could be supported through cross-border health data networks
These pilots demonstrated that multinational secondary use of health data is technically feasible.
At the same time, they highlighted practical obstacles researchers continue to face, including inconsistent coding systems, fragmented governance procedures and differing interpretations of data protection rules.
Why EHDS could reshape HTA and reimbursement
For decades, European HTA agencies have relied primarily on manufacturer-submitted clinical trial evidence when evaluating new medicines and medical devices.
Real-world evidence has been used only intermittently, often constrained by limited access to suitable datasets.
A mature EHDS could fundamentally change this landscape.
With access to large-scale observational data, HTA agencies and healthcare payers could evaluate technologies using far richer post-launch evidence, including:
- long-term effectiveness beyond trial follow-up periods
- comparative effectiveness across real-world treatment pathways
- monitoring of rare adverse events and safety signals
- analysis of healthcare utilisation such as hospital admissions, readmissions and resource use
In practice, this could enable dynamic reimbursement models, where prices, coverage conditions or managed-entry agreements are periodically reassessed as new evidence emerges.
Such approaches already exist in limited forms through outcomes-based agreements, but the EHDS could allow them to operate at far greater scale.
Health data as a strategic economic resource
Beyond its scientific implications, the European Commission also views health data as a strategic economic asset.
Improved access to high-quality, well-governed datasets could accelerate innovation in several fields:
- pharmaceutical development
- medical device research
- artificial intelligence in healthcare
- personalised and precision medicine
Policy analyses suggest that more efficient reuse of health data could generate substantial economic benefits by reducing duplication of research, accelerating evidence generation and improving health system planning across Member States.
The obstacles: standards, governance and trust
Despite its promise, the successful implementation of the EHDS will not be straightforward.
Three challenges are particularly significant.
Data heterogeneity
Healthcare data across Europe are recorded using different coding systems, terminologies and standards. Achieving true interoperability will require substantial investment in data harmonisation.
Governance complexity
Health Data Access Bodies must process large volumes of research requests while maintaining strict privacy protections and regulatory compliance.
Public trust
The long-term viability of EHDS depends on public confidence in how health data are used. Transparent governance frameworks and robust safeguards will therefore be essential.
Towards a European “evidence engine”
Taken together, the EU HTA Regulation and the European Health Data Space point toward a new model of evidence-based healthcare in Europe.
HTA reforms harmonise how clinical evidence is assessed, while the EHDS seeks to transform how that evidence is generated in the first place.
If both initiatives mature successfully, reimbursement decisions may gradually evolve from static launch-time evaluations into dynamic processes informed by continuous flows of real-world clinical data.
In that sense, the EHDS represents far more than a digital health programme.
It is an attempt to build the evidence engine of European healthcare for the coming decades.
Frequently Asked Questions (FAQ)
1. What is the European Health Data Space (EHDS) and why is it important?
The European Health Data Space Regulation is a European Union initiative designed to create a common framework for sharing and reusing health data across Member States.
Its objective is twofold:
- Primary use of data – enabling citizens and clinicians to securely access electronic health records across borders within the EU.
- Secondary use of data – allowing anonymised health data to be used for research, public health policy, regulatory science and health technology assessment.
The EHDS is important because it addresses a longstanding structural problem in European healthcare: fragmented health data systems. By enabling interoperable access to datasets from multiple countries, the regulation could dramatically expand the scale and quality of real-world evidence used to inform regulatory decisions and reimbursement policy.
2. How could the EHDS affect health technology assessment (HTA)?
HTA agencies traditionally rely heavily on randomised clinical trials submitted by manufacturers when evaluating new medicines and medical devices.
The EHDS could change this by enabling access to large-scale observational datasets derived from routine clinical practice.
This may allow HTA bodies to conduct:
- long-term effectiveness analyses beyond trial follow-up
- comparative effectiveness studies across treatment pathways
- monitoring of safety signals and rare adverse events
- analysis of health system outcomes such as hospitalisations or healthcare utilisation.
In the long term, EHDS could support a more dynamic model of HTA, where technologies are reassessed over time as new real-world evidence becomes available.
3. How does the European Health Data Space relate to the EU HTA Regulation?
The EHDS complements the EU HTA Regulation, which introduced Joint Clinical Assessments (JCAs) for new medicines across the European Union.
While the HTA regulation focuses on how clinical evidence is assessed, the EHDS focuses on how that evidence is generated and accessed.
Together these initiatives could form a two-layer system:
• EHDS – provides large-scale real-world data infrastructure
• EU HTA Regulation – harmonises the evaluation of clinical evidence across Member States
In combination, these policies could gradually move European reimbursement systems toward continuous evidence evaluation rather than one-time launch assessments.
4. What role does DARWIN EU play in the EHDS ecosystem?
The European Medicines Agency has already created a real-world evidence network called DARWIN EU (Data Analysis and Real World Interrogation Network).
DARWIN EU operates using a federated data model, meaning that patient data remain in national databases but can be analysed using shared protocols across multiple datasets.
By linking electronic health records, claims data and registries across Europe, the network already supports real-world evidence studies used in regulatory decision-making.
The EHDS is expected to expand this approach beyond medicines regulation, enabling similar federated data analyses for research, HTA and health policy evaluation across the European Union.
5. What challenges could limit the success of the EHDS?
Although the EHDS has the potential to transform health data use in Europe, several challenges remain.
Data interoperability:
Healthcare data across Member States are stored using different coding systems, formats and standards, which makes cross-border analysis technically complex.
Governance capacity:
National Health Data Access Bodies must process research requests efficiently while maintaining strong privacy protections and compliance with EU data protection laws.
Public trust:
Citizens must be confident that their health data will be handled securely and used for legitimate purposes. Transparent governance and clear safeguards will therefore be essential.
Successfully addressing these challenges will determine whether the EHDS becomes a fully operational European evidence infrastructure.
References
Legislation and Policy Documents
- European Health Data Space Regulation.
European Parliament and Council of the European Union. Regulation on the European Health Data Space (EHDS). Brussels: Official Journal of the European Union; 2025. - European Commission.
Proposal for a Regulation on the European Health Data Space. COM(2022)197 final. Brussels: European Commission; 2022. - European Commission Directorate-General for Health and Food Safety.
Impact Assessment Report: European Health Data Space. Brussels: European Commission; 2022. - European Commission.
A European Strategy for Data. Brussels: European Commission; 2020.
Regulatory and Institutional Sources
- European Medicines Agency.
DARWIN EU® – Data Analysis and Real World Interrogation Network. Amsterdam: European Medicines Agency; 2023–2025 programme documentation. - EMA DARWIN EU Coordination Centre.
DARWIN EU Annual Report: Real-World Evidence Studies for EU Regulatory Decision Making. Rotterdam: Erasmus Medical Center; 2024. - European Commission.
HealthData@EU Pilot Project: Cross-Border Health Data Infrastructure for Secondary Use. Luxembourg: Publications Office of the European Union; 2023.
Academic Literature
- Marelli L., Testa G., Romagnoli F., et al.
The European Health Data Space: Too Big to Succeed?
Health Policy. 2023. - Shabani M., Borry P.
Rules for the Secondary Use of Health Data in the European Health Data Space.
European Journal of Health Law. 2024. - Quinn P., Tikkinen-Piri C., Bova C.
Health Data Access Bodies and Governance under the European Health Data Space.
European Journal of Risk Regulation. 2024. - Ohmann C., Canham S., Daniel C., et al.
Sharing and Reuse of Health Data in Europe: The Emerging Role of the European Health Data Space.
European Journal of Public Health. 2023. - Eichler H.G., Bloechl-Daum B., Brasseur D., et al.
Real-World Evidence in European Medicines Regulation: Opportunities and Challenges.
Clinical Pharmacology & Therapeutics. 2022. - Boulanger L., Berta W., Chambers J.D., et al.
Advancing the Use of Real-World Evidence in Health Technology Assessment.
Frontiers in Pharmacology. 2024. - Karanikolos M., Cylus J., McKee M.
Health Data, Governance and Innovation in the European Union.
The Lancet Digital Health. 2023. - European Network for Health Technology Assessment.
Use of Real-World Evidence in Health Technology Assessment. EUnetHTA Methodological Framework; 2021.