Johnson announced five tests for ending lockdown yesterday evening. They were:
1) Making sure the NHS has capacity;
2) A 'sustained and consistent' fall in the daily death rate;
3) Rate of infection decreasing to 'manageable levels';
4) Ensuring supply of tests and PPE can meet future demand;
5) Being confident any adjustments would not risk a second peak that would overwhelm the NHS.
The problem is that these tests make almost no sense at all.
The first reason for saying so is that the first duty of medicine is to do no harm. This is as true of public health as it is of any other part of the discipline. And creating NHS capacity has done harm.
People have been forced to die at home.
Others have been denied access to hospital from care homes.
People were forced out of hospital and into care homes, taking risk with them.
And people are now frightened to go to hospital.
I am told there were 400 empty beds in Addenbrookes Hospital in Cambridge at the weekend. That should not be happening. There are people suffering to create that NHS capacity. That makes it a very poor test.
Second, the death rate is not defined. Is that Covid or excess deaths? And is it real i.e. time lagged data that is likely to be right but takes time to compile, or the widely discredited daily press conference data that no one now really believes?
As epidemiologists tell me, the only potentially reliable death rate is the excess deaths data. But, this is not a good indicator of the success of lockdown because this data is not independent of the lockdown itself. That’s because, as already noted, some people are dying in care homes who need to be in hospitals, whilst others without Covid are simply not going to hospital when they should. There is then a feedback loop that makes this data an unreliable indicator as well. So what does this test mean?
Third, to know the rate of infection there has to be mass testing to establish R. But as Sir David Speigelhalter noted in comments made to Andrew Marr yesterday, there is no testing going on that can tell us what R is.
Having a test that that cannot be tested is not a mechanism to create confidence. As a result epidemiological opinion on this varies very widely. Some epidemiologists think the infection rate in London may be 10% now. Others think up to 50% may have had it. That’s not a basis for evidence based policy. The evidence is absent.
Whilst, fourth, the PPE crisis is entirely of the government’s own making. Is that really then a suitable criteria for testing? Reducing rates of your own incompetence is not a good test, I suggest, even if the PPE is required.
And test five restates tests 1 to 4 in various ways and so is not really a test at all.
Johnsons’s delivery was lame, confusing, long and patronising yesterday.
But his content was worse.
This is not a government sending out good messages. And I believed that messaging was the one thing it did well. As a result the case for confidence is very limited. What is certain is that these tests cannot be the basis for reliable decision making as they stand. In fact, they’re just smokescreen. And that won’t do.