Regular readers of this column will recall that my main effort has been to focus attention on the number of hospital admissions as the key to release from lockdown: once there is no danger of the NHS being overwhelmed then, I submit, the lockdown restrictions on our lives -that are so costly- should be lifted.
Alas, the goal posts have been moving from hospital admissions to the number of infections, or the number of deaths. The danger arising from this ‘mission creep’ is that we will find it ever harder to escape from lockdown at all, with evermore devastating economic and social consequences.
Last September I raised the issue of ‘false positives’ in the Commons with the Secretary of State. I was not satisfied with his answer (see my blog https://www.desmondswaynemp.com/ds-blog/false-positives/ ). Now however, given the shift in policy towards a target of reduced infections, typically being touted at below 1000 new cases daily as the condition for lifting lockdown, the issue of false positives will loom ever larger.
I have seen estimates for false positives ranging between 1% and 6% over the last year. The Secretary of State told us it was 1%. Inevitably, it will vary dependent upon the type of test and the different laboratories processing results.
Let’s be really conservative however, and take the published false positives figure for the lateral flow test at a mere 0.32%.
Now, imagine that Covid-19 died out overnight -it completely disappeared off the face of the earth.
Nevertheless, with 500,000 or so tests carried out the next day we would still detect 1,600 new cases from the false positives and consequently refuse to lift the lockdown.
It gets worse because the ambition is to increase the level of testing tenfold in project ‘Moonshot’ , so the false positives will take us ever further from the desired level of infections.
The same principle will apply to any target based on the level of deaths from Covid-19, because all hospital cases are tested on admission and weekly thereafter.
The only sensible discussion of ‘acceptable’ death rates from Covid-19 would have to be based on a ‘tolerable’ excess over the current winter deaths from all respiratory conditions which, pre Covid-19, was typically 300 per day. Any question of tolerable death levels, is sensitive one, which is why it is essential to stick with a daily level of hospital admissions with which the NHS can deal effectively.
So don’t move the goal posts.
(I am indebted to Professor Anthony Brookes of The Department of Genetics & Genome Biology at University of Leicester)