The additional risk of dying for those over 55 infected with Covid-19 during the peak of the UK epidemic was slightly more than the normal risk of death from all other causes over one year, an expert has said.
An analysis by statistician Professor David Spiegelhalter found that the risk of catching and then dying from Covid-19 for that age group was equivalent to experiencing around five weeks’ worth of extra risk on top of the “normal” risk of mortality from other causes.
This risk decreased steadily with age, corresponding to just two additional days above the normal annual risk for schoolchildren, he said.
Prof Spiegelhalter’s findings, published in the British Medical Journal, are based on analysis of death certificate data for England and Wales over a 16-week period between March 7 and June 27, 2020.
Prof Spiegelhalter, who is chair of the Winton Centre for Risk and Evidence Communication at the University of Cambridge, found the data on deaths from Covid-19 showed an association with age that closely matched the normal risk people all face from death from all other causes each year.
He wrote: “The relation of Covid-19 mortality risk with age is slightly steeper than it is for normal actuarial risk, but for ages over 45 the lines are fairly parallel, indicating that the average risk of catching and then dying from the virus were roughly proportional to the average normal risk over the same period.”
His analysis showed the death rate during the 16-week period was around 12-13% higher for each year older, corresponding to doubling for every five to six additional years of age.
One in 50 people over 90 died with Covid-19 over this period, he said, compared to one in 2,300,000 schoolchildren aged between five and 14.
Prof Spiegelhalter said that although age seems to be the dominant influence on mortality, other factors, such as pre-existing medical conditions, can also affect individual risk.
He also emphasises that the findings are based on past infection rates in the population and cannot be attributed to the future risks of getting Covid-19 and dying.
