Designing Future-Proof Healthcare APIs

If you’ve spent any time in UK healthcare IT, you’ve probably heard the term “APIs” thrown around constantly. But here’s the kicker: it’s not just about connecting systems for the sake of it. In a world where FHIR, openEHR, and the NHS App are becoming central to patient care, designing APIs that are future-proof is critical.

Think about it. Every day, hospitals, GP practices, community care providers, and even patients themselves generate massive amounts of data. Lab results, prescriptions, allergies, imaging, referrals—the list goes on. But this data is only useful if it flows seamlessly to the right place at the right time. That’s where healthcare APIs come in.

Today, I want to take you through how to design APIs that not only work today but can evolve with the NHS, incorporating FHIR, ensuring interoperability, and meeting the UK’s strict information governance requirements.

Why Future-Proof APIs Matter in UK Healthcare

Let’s set the stage. The NHS is moving towards a connected, patient-centred digital ecosystem. Integrated Care Systems (ICSs) aim to share patient records across hospitals, GPs, and community services. The NHS App lets patients book appointments, order prescriptions, and view their health data. Even clinical research increasingly relies on digital data from NHS systems.

But here’s the problem: traditional EHRs and healthcare systems were built in silos. They weren’t designed for modern interoperability. That’s why we see challenges like:

Duplicate records across different systems.
Clinicians manually chasing information from other hospitals or practices.
Patient data locked in proprietary formats, hard to share with apps or research platforms.

Future-proof APIs solve this by ensuring that:

Data can move seamlessly between systems.
APIs are standards-based, so new apps can plug in without constant rewrites.
Systems remain compliant with UK healthcare regulations and information governance requirements.

The Role of FHIR in Building Future-Proof APIs

If there’s one standard that has reshaped healthcare API design in the UK, it’s FHIR (Fast Healthcare Interoperability Resources).

FHIR is a modern standard that defines how health data should be structured and exchanged. It’s built around resources, such as Patient, Observation, MedicationRequest, and Condition. These resources are consistent across systems and can be accessed via RESTful APIs using modern web standards like JSON or XML.

In the UK, FHIR UK Core provides a localised specification, making sure FHIR APIs align with NHS requirements, such as:

Using NHS Numbers as unique patient identifiers.
Integrating with SNOMED CT UK and dm+d (Dictionary of Medicines and Devices) for coding clinical information.
Ensuring patient data can be shared safely across GP practices, hospitals, and the NHS App.

By designing APIs using FHIR UK Core, you ensure your system speaks the same language as the rest of the NHS. That’s the first step to future-proofing.

Principles of Future-Proof API Design in Healthcare

So, what does it actually mean to design future-proof healthcare APIs? Let’s go through some guiding principles.

1. Standards First

Always base your API on widely accepted standards like FHIR, HL7, and UK Core profiles. Standards ensure your API can integrate with multiple vendors and NHS systems without bespoke adapters for every new client.

2. Versioning and Backward Compatibility

Healthcare systems evolve slowly, but APIs need to evolve faster. Always design your API with versioning in mind, so that new versions don’t break existing integrations. For example, if you update the Observation resource to include a new vital sign, older clients should still be able to access the previous fields.

3. Security by Design

Patient data is sensitive. APIs must use strong authentication and authorization protocols such as OAuth 2.0, and integrate with the NHS Login system for patient-facing apps. Encryption in transit (TLS) and at rest is essential.

4. Robust Error Handling and Logging

When dealing with multiple NHS systems, things will inevitably go wrong. A future-proof API should provide clear error messages, detailed logs, and audit trails that comply with UK information governance and DSPT requirements.

5. Extensibility

Healthcare needs change fast. Today it might be lab results; tomorrow it might be genomic data or wearable device readings. APIs should be designed with extensibility in mind, allowing new resources or fields to be added without disrupting existing clients.

6. Interoperability and Mapping

Not every system uses the same coding standard. A future-proof API should map different terminologies, such as converting local codes to SNOMED CT or dm+d when sharing data. This ensures consistency across the NHS ecosystem.

Building APIs That Work with OpenEHR

Many NHS Trusts are also adopting openEHR as a storage standard for clinical data. Here’s how future-proof API design intersects with openEHR:

OpenEHR repositories act as the single source of truth for patient data.
APIs expose parts of this data using FHIR UK Core to other systems or apps.
This separation—storage standard vs exchange standard—means you can change your EHR vendor or internal database without breaking your API consumers.

In other words, the combination of openEHR storage and FHIR APIs is a powerful recipe for building NHS-ready, future-proof healthcare systems.

Ensuring Compliance and Information Governance

No conversation about NHS APIs would be complete without discussing information governance. A future-proof API isn’t just about technical design—it’s about legal and ethical responsibility.

Key considerations include:

Patient Consent – Ensure your API respects opt-ins and opt-outs for data sharing.
Role-Based Access – Only clinicians and authorised personnel should access sensitive data.
Audit Trails – Log every access to patient data in a tamper-proof way.
Data Minimisation – Only expose the data necessary for the task.
Regular Security Reviews – APIs should be tested regularly for vulnerabilities.

These aren’t optional; in the UK, they’re required under GDPR, Data Protection Act 2018, and NHS DSPT frameworks.

Real-World Examples of Future-Proof API Design in the NHS

Let’s look at how NHS organisations are implementing these principles today:

NHS App – Uses FHIR UK Core APIs to provide patients with access to GP records, repeat prescriptions, and vaccination history. It’s secure, standards-based, and continuously updated.
GP Connect – Provides APIs that allow secondary care systems to pull GP records seamlessly. It’s built with robust versioning and audit trails to maintain information governance compliance.
Shared Care Records in ICSs – Multiple NHS Trusts can share patient data in real time. APIs are designed to handle multiple data sources, map terminologies, and support future expansion.

These examples show that future-proof API design is not theoretical—it’s already happening across the UK healthcare system.

Common Pitfalls to Avoid

Even with best intentions, many projects struggle. Some common mistakes include:

Ignoring standards – Creating proprietary APIs may work in the short term but leads to costly integration headaches later.
Skipping governance – Failing to implement robust information governance can result in breaches and legal liability.
Hardcoding values – For example, embedding local codes instead of using SNOMED CT or dm+d makes it hard to scale nationally.
Lack of documentation – Poor API documentation frustrates developers and slows adoption.
Rigid design – APIs that cannot evolve or accommodate new resources will become obsolete quickly.

Avoiding these pitfalls is essential to creating APIs that remain valuable for years.

The Future: AI, IoT, and Beyond

Future-proof APIs don’t just serve today’s needs—they anticipate tomorrow’s. In the NHS context, this could include:

AI-driven decision support – APIs delivering real-time lab results to AI models for diagnosis or risk prediction.
Wearables and home monitoring – Patients sending data from glucose monitors or blood pressure cuffs directly into their GP records via secure APIs.
Population health analytics – Aggregated, anonymised data flowing through APIs to support public health initiatives.
Genomics and personalised medicine – APIs that handle complex, structured data sets for precision treatment.

By designing APIs that are standards-based, secure, and extensible, NHS systems can be ready for all of this innovation.

Key Takeaways

Designing future-proof healthcare APIs in the UK isn’t just about technology. It’s about building a foundation for interoperability, patient empowerment, and innovation, while staying fully compliant with NHS information governance.

Here’s the summary:

Use standards like FHIR UK Core to ensure consistency across NHS systems.
Plan for evolution with versioning and extensibility.
Prioritise security and governance from day one.
Design for interoperability, mapping terminologies and connecting with openEHR repositories where appropriate.
Document and communicate your API clearly to all stakeholders.
Anticipate future needs like AI, wearables, and genomics.

Do this, and your APIs won’t just work today—they’ll scale with the NHS for years to come.

The bottom line? The NHS is moving toward a connected, data-driven future. FHIR, openEHR, and robust information governance are the cornerstones. And at the heart of it all are future-proof APIs—designed not just to exchange data, but to empower clinicians, patients, and innovators alike.