VALO2 non-small cell lung cancer (NSCLC) pilot: lessons learned

Summary

The European Health Data Space (EHDS) aims to make the secure secondary use of health data for research, innovation, policymaking and public health more efficient across Europe (Regulation (EU) 2025/327). Achieving this ambition requires more than legislation and technical infrastructure. The Value from Nordic health data (VALO) initiative was a Nordic collaboration established to explore and advance practical approaches for cross-border secondary use of health data. As part of this initiative, the VALO2 pilot study examined whether researchers could access and analyse cross-border patient-level health data using existing Nordic secure infrastructures.

Danish researchers analysed data held by Helsinki University Hospital in Finland and Oslo University Hospital in Norway within the Secure Processing Environments used by those organisations, while the corresponding Danish analysis was conducted within the research team’s established local environment. Building on the foundations established through the initial VALO1 pilot study and adoption of the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM), the VALO2 pilot study shifted the focus from locally executed federated analysis towards the practical realities of cross-border researcher access, generating insights into the operational, governance and service requirements needed to support future EHDS implementation.

The VALO2 pilot study demonstrated that cross-border analysis was operationally feasible through the Finnish and Norwegian Secure Processing Environments tested as external researcher-facing pathways, alongside local analysis in the Danish team’s established environment. Analyses were completed using Danish, Finnish and Norwegian data. Outputs were released from all three environments, with Finland and Norway using defined review or approval pathways and Denmark operating under researcher and principal investigator responsibility. However, demonstrating feasibility does not automatically translate into scalable operational services. Approval, workspace entry, access to study data and readiness to perform analysis were separate milestones, each affected by governance, permissions, tooling, data preparation, documentation, local support and output release arrangements.

Three broader lessons emerged. First, differing interpretations of ethical and regulatory requirements at organisation and country level can materially change approval pathways and timelines. Second, adopting a common data model did not eliminate the need for protocol-specific feasibility assessment, local validation, and assessment of analytical comparability. Variables required by the study protocol were not always available at every site, consistently mapped and defined; included within approved data extractions; or sufficiently comparable across sites to support pooled analysis. Third, local data, clinical and institutional expertise remain essential to scientific validity, cohort validation and efficient study delivery.

The findings indicate that the EHDS readiness depends on technical, governance and service interoperability. Secure environments and lawful access must be complemented by transparent, sufficiently consistent researcher services and validated analytical workflows. Future readiness assessments should therefore distinguish between secure infrastructure, research-ready environments and operationally mature EHDS services.

Drawing on the findings of the VALO2 pilot study, the pilot team recommends a Nordic Secure Processing Environment maturity model, a common cross-border service profile, study-specific readiness packs, protocol-to-data feasibility checks, workflow readiness testing and common onboarding principles. The challenge is now to translate existing Nordic capabilities into transparent, repeatable and scalable services that make cross-border health data routine rather than exceptional.