February 18, 2021

expert reaction to study estimating years of life lost globally to COVID-19

A study published in Scientific Reports estimates that over 20.5 million years of life may have been lost due to COVID-19.

Dr Richard Wood, Head of Modelling and Analytics at Bristol, North Somerset and South Gloucestershire Clinical Commissioning Group and a Visiting Research Fellow at University of Bath School of Management, said:

“This is a really interesting paper, although with no reference of intensive or critical care.  A further angle could be to investigate what proportion of the 20.5 million “life-years lost” referenced here could be saved by strategies such as ‘reverse triage’ in intensive/critical care (the approach investigated in our recent study published last week in Medical Decision Making1, which also looks at “life-years lost”).  Reverse-triage is an approach prioritising patients with the greatest chance of surviving admission, usually based on age.  It is important that this type of approach is considered alongside important ethical considerations about which patients should be prioritised for admission and the appropriate conditions for discharge.

“This additional angle would require an estimation of the proportion of the 20.5 million life-years lost that are attributable to patients not being able to access intensive care to come out with a figure.  For example if 10% is used as an estimate (i.e. 2.05 million), this could mean that 246,000 life years that could be saved through the use of reverse-triage (based on the 12% finding in our paper in Medical Decision Making).  But this information is hard to come by, so it will need further research and investigation.  Even finding figures for just one country would be very interesting.  Informed policy responses, based on data and modelling, can have a real impact on “life years lost”.”

1 https://journals.sagepub.com/doi/full/10.1177/0272989X21994035 and https://www.hdruk.ac.uk/news/new-model-finds-triaging-covid-19-patients-for-intensive-care-can-reduce-life-years-lost-by-at-least-12-per-cent/

Prof Kevin McConway, Emeritus Professor of Applied Statistics, The Open University, said:

“This is a valuable piece of research, not least because it looks at the impact of the pandemic globally, so not just in high-income countries like the UK.  However, the results can’t show the whole picture.  That’s mostly because of limitations in the available data.  Most of the analysis is based on counts of deaths, at different ages, that have been attributed to Covid-19, but the way deaths are attributed to Covid-19 isn’t consistent across countries and is considerably less complete in some places than others.  Also, most of the results reported here can’t take into account deaths that arose indirectly because of Covid – for instance, deaths because health services were overwhelmed and couldn’t deal with other illnesses so well – or non-Covid deaths that might have been avoided because lockdowns reduced other infections as well as the new coronavirus.  The researchers do partially deal with that aspect by also including an analysis based on excess deaths from all causes, but they could do that for only 19 of the 81 countries included in their main analysis, because of the lack of relevant data for the others.  This excess deaths analysis indicates that the huge number of years of life lost in the main analysis, 20.5 million, is probably a gross underestimate.  The true number might be three times as big.  Another important limitation is that this research doesn’t take into account the effects of illness and disability from Covid-19 that have not (yet) led to death.  Including some measure of the loss of healthy life from these aspects would have made the picture look even worse.

“But the numbers here do provide a broad picture that’s far from misleading, in my view.  Looking at years of life lost gives more weight to a death of a young person, who would otherwise (on average) have many more decades to live, than to the death of someone in their nineties.  That’s not to say that the young person’s death is somehow more important – it’s just another way of measuring the impact of a disease or cause of death.  Some of the discussion of Covid deaths in the UK, and some other richer countries, has argued that the great majority of deaths have been in older people who did not have many more years to live anyway.  That view can verge on the distasteful suggestion that somehow those deaths don’t matter much – but this research indicates that it isn’t even true, not when one looks on a global scale anyway.  Overall, about 30% of the years of life lost, globally, were in people aged under 55, most of whom could have expected several more decades of life.  In many countries, most of the life lost was in people under 55.  That applies in several low-income countries, where the population is often on average younger than in rich countries, but it applies to some middle or higher income countries as well (Lithuania, Romania, South Africa), and in countries including Iceland, Malta and Cyprus, a third of the years of life lost were in under 55s.  Arguably it’s countries like the UK, Sweden, France, Spain and Italy that are most out of line with the global picture, with most years of life lost in people aged 75 and over.  On average across all the countries included, which are all the countries that recorded at least one Covid-19 death in the databases that were used, each Covid-19 death accounted for 16 lost years of life.  (And, to clarify, these researchers didn’t just decide to say that every Covid death in the world accounted for 16 years of lost life – their calculations took into account the actual age that people died and the average additional number of years that a person of that age, in that country, would expect to live if they had not died from Covid-19, and the figure of 16 years lost is the global average that emerged from that process.)

“The comparison in years of life lost between Covid-19 and other causes of death is instructive too.  In countries heavily affected by Covid-19, it has led to far higher loss of life years than seasonal flu – for instance, between 2.5 and 3 times as many lost years in the UK.  In most countries, the loss of life years from Covid-19 has been smaller than the loss from heart disease, but heart disease is one of the most important causes of premature death across the world.  In the UK we’re well aware of the serious and continuing toll of heart disease, and we absolutely mustn’t forget about that, but this analysis found that the loss of life years from Covid-19 here was almost half as big as that from heart disease.  That’s a big impact.  On average across all these countries, years of life lost to traffic accidents were similar to years of life lost to Covid-19, but, like all these comparisons, things vary a lot between countries.  Here the UK is exceptional in that almost 8 times as many years of life were lost from Covid-19 as from traffic accidents.  That’s saying as much about the relatively low numbers of traffic accidents here than in almost all other countries as it is about Covid-19 – but it’s another way of illustrating the huge impact of Covid-19 deaths here.”

Dr Simon Clarke, Associate Professor in Cellular Microbiology at the University of Reading, said:

“This study shows the staggering scale of the human cost of this pandemic.  Every one of those deaths is a tragedy for a family, but this paper highlights the combined cost of the pandemic so far in terms of lives cut significantly shorter by a virus that kills people earlier than seasonal flu, or even heart disease.  These data offer more insight than merely looking at the average age of death from Covid-19 in order to weigh it against the economic cost of restrictions.  Policy decisions made on the basis that Covid-19 mostly kills people with few years of life left, fail to properly appreciate the full impact of Covid-19 mortality.

“It is true that with this disease, mortality rates are the highest in the elderly.  But in the UK, coronavirus is causing the deaths of enough people who are still of working age or in early stages of their retirement to account for half of all the years of life snuffed out by Covid-19.

“This is a reminder that Covid-19 is killing thousands of people in their prime, not just those who were already likely to die from something else anyway.  Those arguing that the economic and social costs of measures to contain the virus are too high should read this carefully, as it is a reminder that deaths come with economic and social costs of their own, as well as being individual tragedies.

“The findings of the study appear to be sound, using data from over 1.27 million deaths from the wide range of countries with different standards of living.”

‘Years of life lost to COVID‑19 in 81 countries’ by Héctor Pifarré i Arolas et al. was published in Scientific Reports at 16:00 UK time on Thursday 18 February 2021.

DOI: 10.1038/s41598-021-83040-3

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

Declared interests

Prof Kevin McConway: “I am a Trustee of the SMC and a member of its Advisory Committee.  I am also a member of the Public Data Advisory Group, which provides expert advice to the Cabinet Office on aspects of public understanding of data during the pandemic.  My quote above is in my capacity as an independent professional statistician.”

None others received.