1/ A lot of interesting discussion recently on NHSX contact tracing app proposals in the UK following on from innovations in Singapore, South Korea and Israel. Some thoughts on what we know so far from an epi / tech perspective #thinkingoutloud

2/ Tracking technology -the NHSX/Apple/Google partnership plans to use Bluetooth low energy (BLE) -the same tech we use for detecting AirPods and Shopping mall apps use to tell us where the nearest Primark is. Most estimations show BLE can register a nearby device up to 100m....

3/ But what are we defining as a close contact? BLE apps can measure distance and duration of proximity. BLE also goes through thin walls - is the family in the flat next door now a close contact?

4/ Apple/ Google are planning on creating distance thresholds for BLE, how are these going to be defined? Singapore are using 'within 5 meters for 30 minutes' - how sensitive/ specific is this? We need to learn lessons from Singapore's approach.

5/ The technology relies on users installing the NHSX app. For it to be effective in the UK an estimated 60% adoption rate is needed (40 million). Singapore, with arguably a more government compliant culture, have managed a 12% adoption rate.

6/ Security - In theory Apple / Google's proposed method make it very hard to hack tracing IDs and COVID status. But it's very hard to absolutely guarantee the app user's anonymity.

7/ Although it seems clear user data is never centralised, how acceptable is an app that tracks location and medical information to the British public in terms of privacy? (side note - has anyone ever read the iTunes terms and conditions?.... Didn't think so)

8/ Trolling - To avoid trolling and hypocondriac users submitting they have COVID - NHSX are piloting the use of codes which are provided with a confirmed laboratory result to avoid false reports.

9/ Timing - It is clear the BLE apps have the potential to make the very resource intensive task of contact tracing MUCH more effective. However, is this intervention too late? Arguably this would have been effective back in January. It may prove useful in later stages.

10/ Despite a number of unanswered questions - BLE tech really does have the potential to change the way we contact trace at a time we really need it. However, it will require a cultural shift, robust privacy assurances and transparency on how data is used.