There follows a guest post from our in-house doctor, formerly a senior medic in the NHS, who draws attention to the errors made repeatedly by the modellers and government advisors and the huge implications of them.
Napoleon Bonaparte remarked that “history is the version of past events that people have decided to agree on”. When the official version of the pandemic is written, I wonder what analysis will be made of the role of statistical modellers and public health experts in driving Government policy over the last 18 months?
To inform this question it may be helpful to examine the recent evidence of how predictions have matched up to real events. For example, on September 8th, SPI-M-O (one of the multitudinous acronym salad bodies advising the Government), produced a paper entitled “Medium-term projections“.
Perhaps mindful of the woeful inaccuracy of previous predictions, the very first sentence heavily caveats the entire document:
These projections are not forecasts or predictions. They represent a scenario in which the trajectory of the epidemic continues to follow the trends that were seen in the data up to September 6th.
If that is the level of confidence the authors of the report have in their own abilities, one rather wonders what value this publication contains – yet this is the level of advice being given to decision-makers.
Firstly, to the “projection” of admissions. The document is in PDF format, so I am unable to reproduce it here, but the graphical representations show a 90% confidence interval fan chart for the period September 12th-28th. Hospital admissions in England are “projected” to be between 600 to 1,200 per day – a fairly wide spread. Graph One shows what actually happened – daily admissions on the blue bars, seven-day moving averages on the brown line.