Owl is beginning to see a number of different ways of analysing the pandemic by examining the emerging data as opposed to using “a priori” modelling. Time will eventually reveal the the “truth”. This is an example of the data analysis approach.
“Coronavirus infections in England and Wales peaked several days before the lockdown came in, a new study suggests, indicating that the draconian restrictions were not responsible for the decline in deaths and cases.”
Modelling by Professor Simon Wood, of the school of mathematics at the University of Bristol, shows that the majority of people who died at the peak would have been infected roughly five days before the lockdown was introduced.
The finding is based on data which shows that the average death from coronavirus takes around 17.8 days from the onset of symptoms, while symptoms appear approximately 5.2 days after infection, making a total of 23 days.
Deaths in England and Wales peaked around April 8-9, which suggests the majority of people who died then had become infected roughly 23 days earlier, around March 18-19.
Full lockdown in the UK did not come into effect until March 25. However, in the week before, social distancing measures were already in place and many people had begun working from home. Large public gatherings had stopped and bars, restaurants and theatres were starting to close.
Prof Wood said: “It does seem possible that the social distancing that was happening before full lockdown might have done the trick.
“My results simply suggest that if you do not make strong assumptions about what happened, then the data tend to suggest a peak a few days before lockdown.”
He said it was difficult to be completely sure when infections peaked in Britain because community testing was stopped in mid-March so there was no data from early in the epidemic.
However his analysis also showed that Sweden’s infections peaked just a few days after Britain, even without full lockdown being imposed in that country. The German reproduction ‘R’ number was also estimated to have fallen below one before full lockdown.
In the work, published on the open access research site arXiv, hosted by Cornell University, Prof Wood said the results had ethical implications for keeping lockdown in place or reinstating it later in the year because it could have disastrous long term implications on the nation’s health.
“These facts have implications for the policies to be adopted in the coming autumn, particularly given the peculiar ethical issues associated with lockdown,” he said. “For example, plausible estimates of the life loss burden from an unmitigated Covid-19 epidemic in the UK are about two weeks per person.
“A plausible lower bound on the UK life loss from the 2008 financial crisis and its aftermath is seven weeks per person. The economic shock from lockdown is substantially larger than 2008.”
Commenting on the research, Professor Carl Heneghan, director of the Centre for Evidence-Based Medicine at Oxford University, said data from the Royal College of GPs (RCGP) showed a similar fall in respiratory infections in the week beginning March 15.
Figures show new infections fell off a cliff even though lockdown would not be in place for a further nine days, leading to the conclusion that social distancing was already working and having a major impact on disease transmission within the community.
“The effect is in line with the RCGP surveillance data which shows the drop in consultations of acute respiratory infections for the week of the 15th March,” Prof Henegan said.
He also found that calls to NHS 111 peaked on the day lockdown was implemented, even though reported infections should have kept rising for several days afterwards because many people would have been incubating the virus and would not develop symptoms for around five days.
The figures suggest infections had actually peaked five days earlier.
Professor Sir David Spiegelhalter, Winton Professor of Public Understanding of Risk in the Statistical Laboratory at the University of Cambridge, added: “I would not be surprised at this – peak deaths were on April 8, only 16 days after lockdown.”