An unevaluated, underdesigned, and costly mess

Quick turnaround mass testing for covid-19 is to be made available to everybody, initially to those without symptoms, across England at a cost of £100bn (€110bn; $130bn).1 This follows a still uncompleted “pilot” in Liverpool, which started on 6 November at the invitation of Liverpool City Council in October, after incidence had peaked. The objective is “to demonstrate that massive asymptomatic testing can help identify far more cases and break the chain of transmission of coronavirus.”2

Participation in this pilot is voluntary. There is no call or recall. All participants receive two tests, the standard PCR test and the rapid turnaround (within 1 hour) lateral flow Innova test. Those with a positive result in either test are asked to self-isolate and are registered with the national track and trace programme, which initiates contact tracing. Key workers, health and social care staff, school staff, and children aged 11 and over are being targeted, but anyone can get tested, preferably at least twice within two weeks.

This is a screening programme, not opportunistic case finding: people are invited to have a test they would not otherwise have had, or asked for. If judged against the criteria drawn up by the UK’s National Screening Committee for appraisal of a programme’s viability, effectiveness, and appropriateness,3 it does not do well and has been already roundly criticised.4

Many asymptomatic people testing positive for covid-19 are probably relatively uninfectious.5 Evidence suggests at least a half may develop symptoms6 requiring self-isolation without the need for a test. Since few currently adhere to self-isolation,7 this is an obvious area for improvement before we embark on an expensive screening programme. Without a systematic approach to call and recall, those most at risk of being infected and transmitting may be least likely to present for screening.8

Source: https://www.bmj.com/content/371/bmj.m4436