The epidemiological impact of the NHS COVID-19 App

Study estimates 6% of individuals receiving exposure notifications from the app subsequently tested positive. Modelling estimated that 284,000 cases were averted by the app, and that for every percentage point increase in app users, the number of cases can be reduced by 0.8%.

SPS commentary:

The study investigated the impact of the NHS COVID-19 app for England and Wales, from its launch on 24 September 2020 through to the end of December 2020. Two approaches were used, with modelling giving the most conservative estimates. The use of statistical comparison of matched neighbouring local authorities resulted in an estimated 594,000 (317,000-914,000) cases averted by use of the app in this time period, with each percentage point increase in use of the app reducing the number of cases by 2.3%.

Nature