The Covid testing trap

9 October 2020

9:59 PM

9 October 2020

9:59 PM

We are in a time where money has lost meaning and value, so perhaps the £10 billion plus spent on Test and Trace doesn’t merit comment. But what do we get for our money? Well, we get a daily case tally which provides headlines for media outlets and endless graphs. We get a regional breakdown which shows us ‘hot-spots’ and we get an army of testers who follow the positive cases. We then find the virus in specific regions, chase it with more targeted testing and usually send the region into local lockdown as more positive cases are identified.

This cycle has been going on in some shape or form since the summer, starting in Leicester and then focusing more in areas in the north west of England. Bolton and Preston were early recipients of the testing merry-go-round but now as viruses in general rise and Covid cases increase commensurately, egged-on by the opening of universities, positive tests are now in the tens of thousands per day. A general rise has been seen across the UK but much more so in large parts of the north west, Yorkshire and Humberside and the north east of England. Local measures have followed, and we appear now to be on the cusp of lockdown-lite (schools and some shops remain open but all hospitality venues close) in these areas.

It would be wrong in my opinion to view this as another exercise of ‘the more you test the more you find’ and ‘what about false positives’? These issues undoubtedly exist and do account for some of the findings but there is a genuine increase in the proportion of positive tests.

So, is this the second wave? I would suggest the answer is: not really. The areas predominantly affected now in the main were lightly affected compared to London and the south east during the initial wave in spring. So perhaps this is still the first wave, albeit highly attenuated, reaching sufficient momentum from prevailing conditions to continue where it left off when summer came. Whatever the term used, this is still clearly a very serious moment for some hospitals and the millions of people affected.

Testing has been contentious for several reasons. Some of these issues are concerned with process and delivery. But this, to me, is ultimately less important that the fundamental problem: does testing give you meaningful data?

Getting a positive result, notwithstanding a false positive risk, reveals you have been exposed to the virus and need to self-isolate. But after your contacts are traced and their contacts traced, testing is targeted and so the chance of a positive test increases. The ‘sample’ tested ceases to be ‘random’. It’s why it is statistically questionable to compare not just the number of positive tests day-to-day but also the proportion of positive tests per 100,000 population over time in specific regions.

Yet even the scientists advising the government appear to so do. This explains why once a region is targeted for testing, it is almost impossible for local restrictions to end. As Keir Starmer observed this week in Prime Minister’s Questions, 19 out of 20 areas of England under restrictions for two months had actually seen infection rates rise.

Here comes the irony. Cities such as Manchester and Liverpool, where there has been most talk of hospital ITUs close to capacity from rising Covid cases, have been under measures for some time already. The problem in these cities seems to have increased, but the response is not to question the measures and the whole paradigm of whether attempting to artificially suppress a virus is possible. Instead the government and the scientists advising them are pushing for more restrictions as they attempt just one more bet to win back their money. They are addicted to lockdown and when eventually we have traffic lights to symbolise Covid-risk, red will almost certainly spell the end for many bars and restaurants across large parts of England permanently.

The big problem is this. We have a metric which is just not accurate. Testing is skewed to areas with previous positive tests and does not give us a true reflection of infectivity. The resultant climb in cases feeds anxiety that something must be done. Increased mixing in society which in previous years would be normal is now deemed a public health hazard and the resultant normal rise in respiratory infectious admissions, coupled with an increase in Covid-19, is now leading us further down a path of closure and lockdown until there is nowhere to go. We are following unreliable data with measures which cause serious harm to our overall health and have no proven benefit in reducing overall death. Indeed, some recent modelling, not least from Professor Graeme Ackland at the University of Edinburgh, suggested that lockdowns may actually cause an increase in loss of life.

I feel we are following a moving target by constantly reacting to the daily positive test count. The numbers vary with reporting dates and the population sampled changes. The £10bn Test and Trace system funnels tests to people who are more likely to positive and this simply reinforces the viral suppression strategy the government is wholly committed to. It may seem an obvious reaction if you are presented with desperate scenes from full hospital ITUs but these rises have happened with restrictions already in place. And always never forget, this is not a better safe than sorry strategy because all we are doing is prolonging the epidemic. That means we are potentially exposing more people to Covid-19 over time who may then be severely affected and not only that, we are worsening the health of people with other existing conditions, missing cancers, strokes and serious heart disease and causing untold mental health damage.

That Covid is serious and on the rise, there is no doubt. But the way we are trying to measure and suppress it is very questionable, and we appear intent on digging ourselves further into a hole.


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