Covid: Daily death projections shown at lockdown press conference revised down by 500 following 'error'
The government has been criticised after slides showing stark coronavirus projections at Saturday's lockdown press conference were revealed to have been wrong due to an "error" being found in the data.
Two slides shown by chief scientific adviser Sir Patrick Vallance at the press conference Boris Johnson held to announce England was being placed into a full national lockdown have since been "amended".
As reported by the Telegraph, top-end projections on one slide wrongly suggested deaths would soon pass 1,500 - much more than the first wave peak of 1,073.
The revised projection actually shows daily deaths reaching around the same number as what the peak was in the first wave by December 8.
The original graph projecting daily deaths
The other slide, which showed top-end projections that hospital admissions would soon reach almost 9,000, has also been amended to show a projection of just over 6,000.
The revised slides, which are displayed on gov.uk, now come with the caption: "Plots on slides 4 and 5 have been amended after an error was found in the interquartile ranges for SPI-M medium term projections."
The government says the changes "do not affect the insights that can be taken from these analysis".
The revised graph projecting daily deaths:
The central projections for both slides were unchanged in the amended versions.
Boris Johnson's spokesperson said the error related to a "mistake in plotting confidence intervals" and it was rectified as soon as possible.
He added how the consensus remains that NHS capacity would soon be breached if lockdown action was not taken.
The slides showed projections by the Scientific Pandemic Influenza Group on Modelling (SPI-M), which provides the government with advice on the UK's response to threats from human infectious diseases.
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The changes were made following criticism from a number of Tory MPs, including former prime minister Theresa May, over the way the government used data to justify England's second lockdown.
Business minister Nadhim Zahawi told ITV News the government would "always strive to improve data " but insisted the lockdown in justified.
"The important fact," he said, is that "we've gone in four weeks from having 2,600 people in hospital four weeks ago, to over 12,000 now and rising."
Former PM Ms May criticised the government over a different slide, also presented by CSA Sir Patrick, which showed there could be 4,000 coronavirus deaths a day by the peak of the second wave.
Sir Patrick, speaking at the Science and Technology Committee on Tuesday, said the figure was a model, rather than a forecast.
He said: "I positioned that, and if that didn't come across then I regret that, but I positioned that as a scenario from a couple of weeks ago, based on an assumption to try and get a new reasonable worst-case scenario."
He defended the use of modelling at press conferences, saying they are "scenarios" rather than predictions.
Speaking in the House of Commons in Wednesday's debate on England's lockdown, Ms May said: "This leads to a problem for the Government - for many people it looks as if the figures are chosen to support the policy rather than the policy being based on the figures."
Political Reporter Shehab Khan explains the data error:
On Thursday, the official statistics watchdog publicly warned Sir Patrick over the Government's use of data during the Covid-19 pandemic.
In a letter to the chief scientist, the Office for Statistics Regulation warned that the lack of transparency surrounding some of the figures meant there was "potential to confuse the public and undermine confidence in the statistics".
Professor Carl Heneghan, of Oxford University, went further, tweeting: "The Government's use of data is not just confusing - the errors are positively misleading."
Asked if Boris Johnson still had confidence in Sir Patrick, a No 10 spokesman said: "Yes, of course."
The spokesman added: "We want to make the data as clear and transparent as we can.
"There was no error in the underlying analysis. The consensus is that without action we will breach the first wave (peak) in terms of hospital admissions.
"We have acknowledged the mistake which we have corrected and we will continue to try and provide data in the clearest possible way."