Over 1.7 million app users across England and Wales have been advised to isolate by the NHS COVID-19 app following a close contact with someone who goes on to test positive, new data published today shows.
The NHS COVID-19 app has been breaking chains of transmission to protect users and their communities since its launch in September.
The app is the fastest way to notify the public they have been at risk of contracting the virus, sending alerts to close contacts to tell them to isolate as quickly as 15 minutes after an app user enters a positive result into the app.
The app has now been downloaded 21.63 million times, representing 56% of the eligible population aged 16+ with a smartphone and was the second most downloaded free iPhone app on the Apple App Store in 2020.
The more people who download the app the better it works. Research conducted by scientists at The Alan Turing Institute and Oxford University shows for every 1% increase in app users, the number of coronavirus cases in the population can be reduced by 2.3%.
Research by the Turing/Oxford team into the epidemiological impact of the app also points to a causal link between app use and reduced case numbers, with their analysis suggesting the NHS COVID-19 app has prevented 600,000 cases since it was launched.
Health and Social Care Secretary Matt Hancock said:
The app has been designed with privacy in mind so it tracks the virus not people utilising the latest in data security technology to protect privacy while notifying users when they are at risk.
As well as contact tracing and booking a test the app allows users to check their symptoms via the symptom checker. Coronavirus symptoms have been reported into the app over 1.4 million times in England and Wales since 24 September.
Over 3.1 million test results have been entered into the app across England and Wales, of which 825,388 were positive. This is a combination of both tests booked through the app and test results manually entered into the app. As users are more likely to manually enter a positive test result in order to trigger contact tracing than a negative result, these figures cannot be used to calculate a positivity rate for the NHS COVID-19 app comparable to manual contact tracing.
Baroness Dido Harding said:
Figures on the app’s wider features show users have checked into a venue over 103 million times. A total of 253 venues were identified as ‘at risk’ as a result of an outbreak since 10 December, triggering ‘warn and inform’ alerts to app users who had checked into those venues, protecting app users by letting them know as quickly as possible when they may have been at risk so they can monitor symptoms. A ‘warn and inform’ notification will only be sent if an outbreak is identified at a venue and is not equivalent to an instruction to isolate.
The app operates on a principle of continual improvement and has had a series of updates since its launch in September 2020, including an update to the risk scoring algorithm to utilise GAEN API Mode 2 which better estimates distance based on Bluetooth signal strength, increasing its accuracy and making this the first contact tracing app worldwide to harness this technology.
Professor Mark Briers of the Alan Turing Institute said:
The app is now also interoperable meaning it is compatible with other contact tracing apps across the UK, protecting users who travel to Scotland, Jersey, Northern Ireland or Gibraltar. As of December, self-isolation support payments have been available to users in England who have been instructed to isolate, without compromising the privacy protecting nature of the app. In Wales NHS COVID-19 app users have been eligible to apply for the SISS since 1 February.
App users will only be notified to isolate if they are assessed to be at risk of having caught the virus so it is essential users comply with self isolation to stop the spread of the virus and protect the NHS.