Clearing the NHS Diagnostic Services Backlog: Tackling Diagnostic Bottlenecks and Improving Efficiency

24th November 2025

by Louisa Mackintosh

NHS Diagnostic services are the engine room of healthcare. From imaging and pathology to endoscopy and cardiology, accurate diagnosis underpins every patient journey. But across the NHS, this engine is struggling to keep pace. Delays, workforce shortages and administrative bottlenecks are holding back patient flow. The result is growing diagnostic waiting times and slower access to treatment.

So, what’s causing the diagnostic bottlenecks? And what does it take to fix them?

The scale of the NHS diagnostic backlog

For years, the NHS has aimed to ensure that less than 1% of patients wait more than six weeks for one of the 15 key diagnostic tests. Yet, NHS England data shows that in mid-2024, more than 365,000 patients had been waiting beyond that threshold. This figure represents the highest level since the early stages of the pandemic.

A shortage of staff and equipment is a major contributor. The Royal College of Radiologists reports that patients in many regions are waiting over a month for imaging results due to limited capacity and a shortage of reporting radiologists. The Health Foundation and The King’s Fund have both warned that without action, these pressures will continue to undermine recovery plans for elective and cancer care.

Delays in diagnosis don’t just affect targets. They have real consequences for patients. A survey by the Patients Association found that nearly one in five respondents felt their long-term recovery had been set back significantly by delays in getting tests or results. Many also described the frustration of not knowing when they would be seen or who to contact for updates.

What causes diagnostic bottlenecks?

Bottlenecks in NHS diagnostic services don’t always stem from a lack of scanners or staff. Often, they also arise from process inefficiencies and fragmented systems.

Referrals are frequently passed between multiple departments, with manual scheduling and phone-based booking. Appointments are sometimes arranged without full visibility of capacity, leading to under-used slots in one site and oversubscription in another. When patients cancel or fail to attend, those slots are often lost because reallocation isn’t automated.

An NHS Improvement report highlighted how delays in transportation, sample handling, reporting and communication all combine to slow the diagnostic pathway. The result is that even when new community diagnostic centres open or more equipment becomes available, throughput doesn’t always improve at the expected rate.

How to improve diagnostic service efficiency

To address these issues, three core principles stand out:

1. Better capacity planning and resource use

Expanding the diagnostic workforce and equipment base remains important, but equally vital is making better use of existing resources. The King’s Fund has cautioned that the success of community diagnostic centres will depend on tackling workflow and coordination challenges, not just adding capacity.

2. Streamlined booking and scheduling

Modern scheduling tools can transform how referrals are managed. Automated systems can allocate appointments in real-time, ensuring high utilisation and reducing cancellations. The Strategy Unit’s 2023 report on diagnostic growth stresses that demand management and workflow improvement are essential if services are to keep pace.

3. Improved patient access and communication

Patients consistently report difficulties booking or rescheduling tests, particularly when contact lines are busy or coordination between sites is poor. Providing digital self-service booking and automated reminders reduces no-shows and gives patients more control.

Technology can’t add more radiographers or MRI scanners overnight, but it can make the system work smarter. Diagnostic booking and workflow platforms provide several practical advantages:

1. Real-time visibility of capacity: A single view of available staff, equipment and locations means bookings can be made more intelligently. This helps trusts make the most of every available slot.
2. Faster referral-to-test process: Automated workflows link referral systems directly to booking, cutting out manual handovers and reducing administrative delay.
3. Patient self-service and reminders: Patients can confirm, rebook or cancel online, freeing up staff time and ensuring unused slots are automatically reallocated.
4. Data-driven insights: Live dashboards help managers track utilisation, identify diagnostic bottlenecks and plan improvements based on evidence.
5. Integration with the wider care pathway: When booking systems integrate with outpatient and EPR systems, clinicians will always have the results they require, reducing lag, wasted appointments and follow-up delays.

These are the kinds of improvements supported by Netcall’s Diagnostic Booking Solution. It helps NHS trusts coordinate diagnostic activity, improve slot utilisation and provide patients with updates and reassurance throughout the process with our patient engagement portal. The approach is already in line with NHS digital and operational priorities: Better flow, reduced diagnostic waiting times and improved experience.

A vision for faster, smarter NHS diagnostic services

Picture a service where a GP referral automatically generates a message to a patient enabling them to book a time and location that is convenient to them, with conformation via the NHS App or text. Test results can be shared promptly with both patient and clinician. Equipment is in use throughout the day, staff workloads are balanced and pathway data informs continuous improvement.

This is not a distant goal. It’s a realistic outcome when digital booking and workflow tools are embedded as part of service redesign. They enable trusts to make the best use of the capacity they already have and to scale efficiently as more resources become available.

Reducing diagnostic waiting times

The diagnostic backlog represents one of the biggest challenges facing the NHS today. Expanding capacity is vital, but without smarter coordination, new resources risk being under-used. Technology offers the key to unlocking those gains.

By simplifying the referral-to-test journey, improving visibility and empowering patients, digital booking solutions help transform diagnostics from a bottleneck into a flow-through engine of care. For trusts and systems determined to deliver faster, fairer access to diagnosis, the next step is clear: Harness the power of intelligent technology to keep the diagnostic engine running smoothly.

About the author

Louisa Mackintosh

Market Manager – Health

Louisa has spent more than two decades in marketing communications, working with international software companies to bring complex ideas to life in ways that resonate with people, most recently specialising in patient engagement technology. She works closely with NHS trusts, helping them make the most of their digital tools so they can focus on what really matters: Supporting patients. When she’s not at work, Louisa enjoys staying active, whether that’s working out or heading out for long walks with her dog. She also loves live music and comedy.