The UK’s NHS COVID-19 app, built using the Apple-Google framework, is set for an update that will send out more self-isolation alerts, BBC News reported. The people leading the project said that a change to the app’s algorithm aims to make contact-matches more reliable.
API Update Prompts Lower Isolate Threshold for NHS COVID-19 App
In a new blog post, Randeep Sidhu and Gaby Appleton, the latest people to lead the project, wrote:
Google and Apple have recently upgraded their API and so we are upgrading the NHS COVID-19 app to take advantage of the improvements they have developed.
The updated API “considers ‘time data’ as well as improved ‘signal-strength’ data,” they explained. This means that “we can better estimate change in distance, and so distance itself, in order to improve distance estimation accuracy.” As a result of the changes to the API, the risk threshold used by the app to trigger an alert telling someone to self-isolate is going to be lower:
“The update to the risk threshold is expected to increase the number of people asked to self-isolate by the app, having been in close contact with someone who tested positive.