Life Expectancy

Putting the Pandemic’s Death Toll Into Perspective

There are two ‘official’ death tolls on the Government’s COVID-19 dashboard. 138,852 is the number of deaths within 28 days of a positive test. 162,620 is the number of deaths with COVID-19 on the death certificate.

The main reason the latter is larger than the former is lack of testing during the first wave. In the spring of last year, about 15,000 people in whose death COVID-19 was a contributing factor died without being tested.

So is 162,620 the pandemic’s true death toll? No. And that’s because it includes a large number of deaths that probably would have happened anyway.

How do we know this? Because if we calculate the excess deaths – the number of deaths in excess of what we’d expect based on previous years – we get a much lower number.

The official death toll for England and Wales, based on death certificates, is 147,031. Yet if we add up all the deaths since the start of March 2020, and subtract the average over the last five years, we get a figure of 117,476 (about 20% lower).

What’s more, due to population ageing, the average over the last five years understates the expected number of deaths. Hence the true number of excess deaths is about 15% lower. Taking this into account, the pandemic’s total death toll in England and Wales is about 100,000.

However, when it comes to events like pandemics, estimating the total death toll isn’t the best way to gauge the impact on mortality. Consider an example.

Japan and Mexico have about the same population, but there are more deaths each year in Japan. How can this be, when everyone knows Japan is a very long-lived country? The reason is simple: there are more elderly people in Japan, so there are more people at high-risk of dying each year.

A better way of comparing the level of mortality in Japan and Mexico is to use the age-standardised mortality rate or life expectancy. Both of these measures take into account the risk of dying at different ages, as well as the age-structure of the population. (In 2019, Japan’s life expectancy was 84, whereas Mexico’s was only 76.)

Last year, the U.K.’s age-standardised mortality rate rose by 12.8%. Although this is the largest one-year change since 1940 (the first year of the Blitz), the level to which mortality rose was lower than in 2008. And even the change should be put into context: 2019 was a year of unusually low mortality.

I previously estimated that the life expectancy in England and Wales last year was 80.4 – down from 81.8 in 2019. (Other researchers have reported similar figures.) So despite tens of thousands of excess deaths, life expectancy was still around 80.

How Much Loss of Life Was Due to COVID-19 in 2020 Compared to Other Diseases?

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.