We’re publishing an original piece today by an engineer called Paul Bird in which he has tried to calculate the total loss of life due to Covid in 2020 in England and Wales. He’s done that by working out the average life expectancy within each population cohort, calculating the average loss of life among those who died ‘involving’ Covid in each cohort, and then producing a sum total: 814,264 years of life lost. He then tries to put that number in context.
It is difficult to relate to numbers like these. What do they mean?
Clearly, the overall size of the population is important. The impact of 100,000 people dying (for whatever reason) in a country of one million is rather more serious than in a country of 100 million.
The population of England and Wales in 2019 was just over 59 million, so 814,264 lost life-years is equivalent to 0.014 life-years per person, or five days.
Again, that figure is difficult to relate to. No-one wants to lose even one day of his or her life. However, the statistic does give the possibility of comparison with other things, such as the life lost to diseases and lifestyle choices we are more familiar with.
It also provides a way to gauge the proportionality of lockdown. How do the collateral harms of lockdown, which everyone is having to endure, compare to the life-time saved by lockdown? (At the time of writing it is not clear how many Covid deaths were saved by lockdown in 2020. Initial work on international comparisons suggests none at all.)
In strictly numerical terms, how does the time period five days compare to average life expectancy of 81.25 years?3 One way of visualising it would be to take a piece of string one metre long representing 81.25 years and cut off a piece representing the lifetime lost to Covid averaged over the whole population. How long would the offcut be? If you had been closely following the BBC’s coverage you might reason as follows: “Well, hundreds of thousands of people have lost their lives to Covid, and there are millions of people in the country, so maybe, I guess, the offcut would be a tenth? 10 centimetres?” That dedicated viewer would be wrong. The actual length of string corresponding to five days is 168 micrometres. That is, less than a fifth of a millimetre, a bit thicker than a human hair. You’d need specialist tooling to make the cut, and the string cut off would disintegrate into individual strands which would be hard to see with the naked eye.
This is an interesting way of looking at the impact of Covid and worth reading in full.