@Nellodee
Neil Ferguson gets a very hard time for his models, made at the beginning of outbreaks. A model is only as good as the data fed into it and in the early stages of pandemics, the data is all over the place. We still need those early models and realistically, we need the worst case models far more than the best case ones, but it is the nature of the beast that they are more likely to be wrong than to be right.
Q1.
In 2005, Ferguson said that up to 200 million people could be killed from bird flu. He told the Guardian that ‘around 40 million people died in 1918 Spanish flu outbreak… There are six times more people on the planet now so you could scale it up to around 200 million people probably.’ In the end, only 282 people died worldwide from the disease between 2003 and 2009.
How did he get this forecast so wrong?
Q2.
In 2009, Ferguson and his Imperial team predicted that swine flu had a case fatality rate 0.3 per cent to 1.5 per cent. His most likely estimate was that the mortality rate was 0.4 per cent. A government estimate, based on Ferguson’s advice, said a ‘reasonable worst-case scenario’ was that the disease would lead to 65,000 UK deaths.
In the end swine flu killed 457 people in the UK and had a death rate of just 0.026 per cent in those infected.
Why did the Imperial team overestimate the fatality of the disease? Or to borrow Robinson's words to Hancock this morning: 'that prediction wasn't just nonsense was it? It was dangerous nonsense.'
Q3.
In 2001 the Imperial team produced modelling on foot and mouth disease that suggested that animals in neighbouring farms should be culled, even if there was no evidence of infection. This influenced government policy and led to the total culling of more than six million cattle, sheep and pigs – with a cost to the UK economy estimated at £10 billion.
It has been claimed by experts such as Michael Thrusfield, professor of veterinary epidemiology at Edinburgh University, that Ferguson’s modelling on foot and mouth was ‘severely flawed’ and made a ‘serious error’ by ‘ignoring the species composition of farms,’ and the fact that the disease spread faster between different species.
Does Ferguson acknowledge that his modelling in 2001 was flawed and if so, has he taken steps to avoid future mistakes?
Q4.
In 2002, Ferguson predicted that between 50 and 50,000 people would likely die from exposure to BSE (mad cow disease) in beef. He also predicted that number could rise to 150,000 if there was a sheep epidemic as well. In the UK, there have only been 177 deaths from BSE.
Does Ferguson believe that his ‘worst-case scenario’ in this case was too high? If so, what lessons has he learnt when it comes to his modelling since?
Q5.
Ferguson’s disease modelling for Covid-19 has been criticised by experts such as John Ioannidis, professor in disease prevention at Stanford University, who has said that: ‘The Imperial College study has been done by a highly competent team of modellers. However, some of the major assumptions and estimates that are built in the calculations seem to be substantially inflated.’
Has the Imperial team’s Covid-19 model been subject to outside scrutiny from other experts, and are the team questioning their own assumptions used? What safeguards are in place?
Q6.
On 22 March, Ferguson said that Imperial College London’s model of the Covid-19 disease is based on undocumented, 13-year-old computer code, that was intended to be used for a feared influenza pandemic, rather than a coronavirus.
How many assumptions in the Imperial model are still based on influenza and is there any risk that the modelling is flawed because of these assumptions?