FHIR and EHDS

What is EHDS?

The European Health Data Space (EHDS) is an EU regulation (2025/327) adopted in March 2025. It creates a framework for two types of health data use across the EU:

• Primary use: patients accessing their own health data and sharing it across borders — a doctor in Slovakia can see your medical records when you are treated in Germany.
• Secondary use: anonymised health data used for research, public health, and AI training — governed by a separate access framework.

EHDS does not build a central EU health database. It mandates that national health systems expose standardised APIs so that authorised parties can access data using agreed formats. FHIR R4 is the mandated technical standard.

Timeline and mandatory datasets

EHRxF — the exchange format

EHRxF (Electronic Health Record Exchange Format) is the technical specification layer of EHDS. It defines FHIR profiles, ValueSets, and Implementation Guides for each mandatory dataset. EHRxF is still being developed — as of mid-2025, the Patient Summary and ePrescription specifications are the most advanced.

EHRxF Patient Summary is built on the International Patient Summary (IPS) — an existing HL7 IG that defines a minimal cross-border patient summary. EHDS extends IPS with EU-specific constraints and national profile layers.

MyHealth@EU — the infrastructure

MyHealth@EU is the EU digital infrastructure that connects national health systems. It was originally built for the eHN (eHealth Network) pilot — a pre-EHDS initiative for cross-border patient summaries and ePrescriptions that has been running since 2019 in several EU countries.

Under EHDS, MyHealth@EU becomes the mandatory backbone. Each member state must connect a National Contact Point for eHealth (NCPeH) to MyHealth@EU. In Slovakia, this is managed by NCZI (Národné centrum zdravotníckych informácií).

Why FHIR is mandated

EHDS does not mandate "REST" or "JSON" in the abstract — it mandates HL7 FHIR R4 specifically. The regulation follows the same path as the US (21st Century Cures Act, also mandating FHIR R4) and Australia (FHIR-based national standards). FHIR became the de facto global standard for health data APIs.

Slovak context

Slovakia's national health IT system is eZdravie, operated by NCZI. As of 2025, eZdravie uses a mix of HL7 v2, CDA documents, and proprietary interfaces internally. The EHDS mandate requires Slovakia to expose FHIR APIs by 2027 for Phase 1 datasets.

This creates a significant migration challenge: existing CDA-based patient summaries (used in eHN since 2019) must be mapped to FHIR-based IPS format. NCZI is responsible for implementing the national NCPeH connector.