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Know your enemy

In just over a year, the UK’s COVID-19 testing capacity increased from a few thousand to hundreds of thousands of tests a day. This achievement has been crucial to the fight against the virus – and the sinews of the system are digital.

Blue box of COVID-19 self-tests

The director general of the World Health Organisation put it simply: “We cannot stop this pandemic if we do not know who is infected.”

As COVID-19 initially spread in the UK, the testing infrastructure necessary to building that knowledge at pace and at scale did not exist.

“There was no national testing service and we stood on top of a complex NHS structure in which many trusts had local testing capability and know-how. It was robust and it did its job, but it was not built for the situation we found ourselves in in March 2020,” says Julian Thomas, head of the COVID-19 testing programme at NHS Digital.

That capability has since been transformed. The numbers are staggering: from 16,000 appointments booked on the first day of a new digital platform at the beginning of April 2020 to a digital infrastructure capable of processing and returning more than 10 million test results per day by May 2021.

In theory it sounds quite simple. But it’s a rather complicated journey.

The testing infrastructure includes a lab capacity of up to 800,000 PCR tests per day as well as an average of 625,000 lateral flow test results logged by people in the community per day since May 2021.

On the busiest day so far, the digital service successfully processed and returned more than 2 million results within 24 hours.

But, to fully appreciate the achievement, it is necessary to understand the complexity of the collaboration behind those numbers. Hundreds of thousands of staff across NHS Test and Trace and thousands of local NHS, not-for-profit, private sector and national organisations were involved in the work. The digital and data integration that underpinned and linked up that effort was only one part of the story, but it was crucial.



An evolving platform

In April 2020, NHS Digital began leading the design, build and deployment of the digital infrastructure needed to support the new testing facilities being developed by NHS Test and Trace, the life sciences sector and academia on top of the Public Health England lab network. NHS Digital has since worked closely with 3 major and many smaller suppliers, 2 home delivery channels and a community of users of this data, including NHS Test and Trace, Public Health England and the devolved authorities, to rapidly establish the digital infrastructure needed to support the evolving national testing service.

By the end of April 2020, a platform to allow key workers to order and take PCR tests and to then track samples and disseminate the results had been established. The platform was then integrated with NHS 111 online, allowing members of the public with symptoms to start to book tests.

In May 2020, bookings were available at drive-through and walk-through centres, mobile units or using home swabs and the system was supporting batch orders of tests for care home staff. The following month, antibody testing and asymptomatic testing was supported before elective procedures could be arranged digitally. Results were automatically being sent to GP’s systems.

We have maintained a product that has been landing, processing and disseminating data within half an hour.

By August, home testing kits could be returned through post boxes and a strategic IT Operations Centre had been set up to monitor and maintain all of the testing programme's digital services. The NHS COVID-19 contact tracing app was integrated with the platform to allow tests to be booked and results returned within the app, while keeping data anonymous.

As the service continued to expand in the autumn, support for mass testing in key settings such as care homes, universities and secondary schools was continuously improved and it became easier for individuals to identify themselves. NHS login was linked to the platform, allowing individuals who needed to be tested multiple times to enter their personal information only once.

In early 2021, population-wide testing started to become a reality. New laboratories and NHS Test and Trace mobile testing laboratory units were integrated into the service and new partners, including the Royal Mail, were allowing a major expansion of services. By March, members of the public were able to order NHS Test and Trace lateral flow tests for home use. Bulk ordering of tests and registering of results by universities, schools and other key settings was fully supported and a new system integrated with third-party hotel booking systems was supporting mandatory testing of international arrivals.

At peak, the digital service successfully processed and returned over 2 million test results within 24 hours. More that 230 million tests digitally processed and returned to date.

Data flows

As the platform iterated, its scale increased massively. In one week of September 2021, 5.65 million people were tested for COVID-19 at least once and 162,000 people tested positive.

But the usefulness of that activity relied completely on getting the key information to the right people.

Richard Steele, data flow lead in the NHS Digital team, is responsible for making that happen. For example, data from people who have booked their own PCR test (Pillar 2) must flow to the NHS Test and Trace service for contacts to be identified.

“We were initially asked to land up to 100,000 results,” Steele says. “After about 4 months, we needed something that could cope with 1 million results a day, and that required changes to the architecture. In December 2020, we started preparing something that could cope with 10 million results a day should the capability be required. We have maintained a product that is delivering and has pretty much from the beginning been landing, processing and disseminating data within half an hour.” This has allowed for the vast expansion of testing in homes, schools and workplaces.

Average of 625,000 self-reporting results uploaded every day since May 2021

Steele’s team has also been responsible for establishing direct data feeds into GP systems so clinicians can see whether their patients have tested positive for COVID-19, a data flow that NHS Digital has never overseen before.

“To do that we have to match and be 100% confident we are matching data to the right patient,” he says. “The difficulties of doing that are considerable, but they are really high if we get poor data quality. That’s an ongoing challenge.”

When the solution to send results automatically to GP systems was first delivered in July 2020, 45% of new results could not be automatically sent because of data quality issues, such as misspelt names. As a result, an additional matching process was established and up-front verification to maximise data quality was introduced. The system was able to match 1.7m historic results with missing or incorrect demographic data because of these measures.

Data and Management Information Lead Emma Summers says, “We do analysis and evaluation from an operational perspective so we can understand where there are data quality issues and where there is a need to make improvements to the digital journey. The more we can do to improve the quality of the data and how that's captured upfront, the better chance we have of matching data into GP records, for example.”

A reliable service

Andrew Coates, Head of the IT Operations Centre at NHS Digital, is responsible for the live, day-to-day service provided by NHS Test and Trace. This covers everything from the moment a member of the public visits a webpage to get a test, to them receiving their test results.

“We have built a committed and knowledgeable service integrator team who deal with any incidents that come in on a day-to-day basis,” he says. “In theory it sounds quite simple, but it’s a rather complicated journey due to the number of different suppliers and interoperable systems involved.”

The setup of multiple different services within short timescales, and the fast pace of change across the services has led to some technical incidents. The service integrator team have worked across all suppliers to ensure these incidents are resolved efficiently and effectively to mitigate any impact to people using the testing service.

The team also co-ordinate and work collaboratively with all providers to deliver continuous service improvements, which have resulted in increases with the availability of the service, and a reduction in the number of high severity service incidents.

“We are delivering a stable, useable service that is making a difference for millions of people,” says Coates.

More than 750 upgrades to the service since the beginning of the pandemic

“We’ve experienced different phases of this endeavour, and our platform now has a huge breadth of capability, with technology and digital experiences and journeys supporting it,” Thomas says.

“To have had the opportunity to do this has been a real privilege,” he adds. "It’s been hard work, but we have built a brilliant team of remarkable people who have worked insanely smart and hard to get this done.

“Now, as we start to enjoy our freedom, we will look at how we support COVID-19 status checking, how testing will sit alongside vaccine data, and how we might start to enable the economy both domestically and through the border with testing programmes.”

A man uses a swab at an NHS COVID-19 testing unit in Uxbridge, west London in May 2021.

A man uses a swab at an NHS COVID-19 testing unit in Uxbridge, west London in May 2021. 

Related subjects

Matthew Lund, who heads up the User Research team that works across the online COVID-19 Testing service, talks about the challenges of ensuring user research remains at the forefront of a vital, fast-moving and high-profile programme.
Kate Every, Service Designer for the NHS Test and Trace programme, looks at how using data and research helped the team meet the challenge of ensuring anyone within the UK population could carry out a lateral flow test for COVID-19.

Last edited: 28 September 2021 2:37 pm