Clinical Data Repositories: OpenEHR in Practice

Let’s have a chat about something that doesn’t often make headlines but quietly shapes the way healthcare IT works in the UK: clinical data repositories (CDRs) built on openEHR.

Now, if you’ve been following digital health in the NHS, you’ll know that interoperability and data access have been hot topics for years. We hear about FHIR APIs, NHS App integration, patient access, and GP Connect—all aimed at breaking down data silos. But there’s another side of the story that often gets overlooked: how we actually store and manage the massive amounts of clinical data that are generated every single day in hospitals, GP practices, and community care.

That’s where openEHR clinical data repositories come into play.

So, let’s unpack what openEHR really is, why it’s being talked about as the backbone of modern UK healthcare systems, how it compares with FHIR, and what it looks like when put into practice in the NHS.

Why Clinical Data Repositories Matter in UK Healthcare

Picture this: every NHS hospital, GP practice, and clinic is generating clinical data constantly. From lab results to prescriptions, allergies to imaging reports, there’s a never-ending stream of information.

But here’s the catch: that data is often locked into EHR vendor systems. Each vendor has its own data model, its own database structure, and its own way of representing the same information. That means moving data between systems is complicated, expensive, and often incomplete.

For patients, this creates the frustrating experience of repeating their medical history to every new clinician. For clinicians, it means treating people without a full, joined-up record. And for the NHS as a whole, it means duplicated tests, wasted time, and a lot of manual work.

A clinical data repository flips this on its head. Instead of the data being tied to a single vendor’s system, the data lives in a vendor-neutral open standard—one that can be used, re-used, and shared across applications. That’s where openEHR comes in.

What Exactly is openEHR?

If you’re not familiar, openEHR is an open standard for health data storage and management. Think of it as a blueprint for how clinical data should be structured, stored, and retrieved in a way that is consistent and vendor-neutral.

The key principles are:

• Separation of clinical knowledge from technology: Clinical models (like how you represent blood pressure, medications, or diagnoses) are defined in archetypes and templates, independent of the database technology.
• Longitudinal patient record: Data isn’t just stored as snapshots; it builds a continuous story of the patient’s health over time.
• Vendor independence: Because the models are open and standardised, you’re not locked into a single EHR supplier.
• Semantic interoperability: Everyone—clinicians, researchers, apps—can read and interpret the data in a consistent way.

So in practice, if you build a clinical data repository on openEHR, you’re saying: “Here’s a single source of truth for patient data, structured in a standard way, that can feed multiple systems—be it an EPR, a FHIR API, or a patient app.”

How Does openEHR Relate to FHIR?

Here’s where people sometimes get confused. openEHR and FHIR are not competitors. They actually solve different problems.

FHIR (Fast Healthcare Interoperability Resources) is all about data exchange. It defines how systems can send and receive structured healthcare data, usually through RESTful APIs. It’s perfect for NHS App integration, GP Connect, and cross-system communication.

openEHR, on the other hand, is about data persistence and storage. It defines how you build a long-term, vendor-neutral repository of clinical data that can last decades.

So, if you think of healthcare IT like a house:

• FHIR is the plumbing that connects everything together.
• openEHR is the foundation where the data actually lives.

In fact, many modern NHS projects use both. You might store data in an openEHR CDR but expose it externally through FHIR APIs. That way, you get the best of both worlds: robust storage and easy exchange.

The UK Healthcare Context: Why openEHR is Gaining Traction

The NHS Long Term Plan makes it very clear: interoperability and patient-centred data are the future. And while FHIR is already the standard for APIs in the UK, organisations are increasingly turning to openEHR for building their clinical data repositories.

Here’s why:

National push for open standards

NHS England has endorsed both FHIR UK Core and openEHR as standards for digital health. The goal is to move away from proprietary silos and ensure data can follow the patient across settings.

Trusts seeking vendor independence

Many NHS Trusts are tired of being tied into long, expensive EPR contracts. By adopting an openEHR CDR, they can separate their data from the application layer, giving them more flexibility to switch vendors or add new systems in the future.

Research and secondary use of data

Because openEHR data is semantically structured, it’s much easier to use for research, analytics, and population health. That’s crucial for the UK’s ambitions around life sciences, AI in healthcare, and clinical trials.

Integration with FHIR APIs

openEHR doesn’t replace FHIR. Instead, many NHS organisations use openEHR internally for data storage, then publish FHIR APIs externally for patient access and app integration.

Clinical Data Repositories in Practice: Real Examples

It’s one thing to talk theory, but let’s look at how openEHR is being put into practice in UK healthcare.

Somerset NHS Foundation Trust has been using openEHR to build a vendor-neutral CDR, allowing clinicians to access unified patient data across different care settings.

Better (formerly Better Meds) has partnered with several NHS Trusts to deploy openEHR-based platforms for electronic prescribing and medication administration.

NHS Digital’s projects are increasingly exploring how openEHR repositories can work alongside FHIR to deliver both storage and interoperability.

What’s exciting is that these aren’t isolated pilots—they’re part of a broader shift. Trusts are starting to think: “Instead of being locked into one EPR system for everything, why don’t we build an openEHR repository and let multiple applications plug into it?”

Benefits of openEHR Clinical Data Repositories

So why go through the effort of implementing an openEHR CDR in the first place? Here are some of the biggest wins:

• True interoperability: Because the models are standardised, data can move freely between systems.
• Long-term sustainability: Patient data is stored in a way that outlasts any single vendor contract.
• Flexibility for innovation: Startups and digital health apps can connect to the CDR via APIs without having to re-invent the wheel.
• Better clinical decision-making: Clinicians see a complete, longitudinal patient record instead of fragmented snapshots.
• Research-ready data: Structured, semantic data is much easier to use for AI, analytics, and population health studies.

The Challenges of Implementing openEHR in the NHS

Of course, it’s not all straightforward. Some of the challenges include:

• Complexity of modelling: Creating archetypes and templates requires clinical and technical expertise.
• Change management: Clinicians and IT teams have to learn new ways of thinking about data.
• Integration with legacy systems: Most NHS Trusts still run a patchwork of old systems that weren’t built for interoperability.
• Costs of transition: While openEHR reduces vendor lock-in in the long term, there are upfront costs to setting up a new repository.

But just like with FHIR implementation, these are challenges of transition, not reasons to avoid it. Once the foundation is in place, the benefits multiply quickly.

openEHR and the Future of UK Healthcare

Looking forward, it’s hard to imagine a modern NHS digital landscape without both FHIR and openEHR working side by side.

FHIR will remain the backbone for data exchange and APIs—driving patient access, NHS App features, and cross-system communication.

openEHR will increasingly become the backbone for data storage and clinical repositories—ensuring the NHS has a reliable, vendor-neutral, research-ready source of truth for patient records.

Imagine this scenario: you visit your GP in Reading, get referred to a hospital in Basingstoke, and later join a clinical trial in London. With an openEHR clinical data repository at the core, your entire health record follows you seamlessly, accessible to clinicians via FHIR APIs and even visible to you through the NHS App. No duplication, no chasing paperwork, no lost history.

That’s the vision—and it’s starting to become reality.

Final Thoughts

So, when we talk about clinical data repositories and openEHR in practice, what we’re really talking about is the future of UK healthcare IT. It’s about breaking the cycle of vendor lock-in, creating data that’s truly interoperable, and building a foundation that lasts decades—not just contract cycles.

FHIR will keep the data moving. openEHR will keep the data safe, structured, and reusable. Together, they give the NHS the best chance of achieving its long-promised digital transformation.

And if you’re a Trust, a clinician, or even a digital health startup, it’s worth keeping a close eye on openEHR. Because whether you realise it or not, it’s quietly becoming one of the most important building blocks of modern healthcare in the UK.