A review article in PubMed.gov published 18th February 2021 by Arolas and others looked at this issue
They analysed the premature mortality impact of COVID-19 by calculating the amount of life years lost across 81 countries covering over 1.279866 million deaths.
They have based their analysis on two large, recently established and continuously growing databases and on two different methodological approaches. One was based on the COVID-19 attributable deaths and for selected countries. The other one was based on estimated excess deaths, comparing recent mortality levels to an estimated baseline.
They found in total 20.507518 million years of life had been lost to COVID-19 amongst the studied 81 countries due to 1.279866 million deaths from the disease. The average year of life lost was 16 years per death.
As countries were at different stages of the pandemic trajectory, their study was a snapshot of the impacts of COVID-19 on years of life lost as of January 6th 2021.
In 35 of the countries in their sample, coverage of the data spanned at least nine months. This suggested that the full impact of the pandemic in 2020 or at least the first waves of the pandemic, were likely to be captured.
For other countries still on an upward trajection transmission rates for which data is yet forthcoming, the years of life lost experienced are likely to further increase substantially in the next few months.
To put the impacts of COVID-19 on years’ life lost in perspective, they compared the figures against the premature mortality impact of three other global common causes of death, heart conditions cardiovascular disease, traffic accidents transport incidents, and the seasonal flu or influenza.
- They found that in the heavily impacted highly developed countries COVID-19 was two to nine times that of the common seasonal influenza that is compared to a median flu year for the same country.
- Between two and eight times traffic related year life lost rates.
- Between a quarter and a half of the year life lost rates attributable to heart conditions in countries.
As had been noted early on in the pandemic, mortality rates for COVID-19 were higher for the elderly, with postulations that this may be due to correlations with the greater likelihood of these individuals suffering from underlying risk factors.
This study sample presents an average age at death of 72.9 years yet only a fraction of the year lives lost can be attributable to the individuals in the oldest age bracket.
- Globally 44.9% of the total year lives lost can be attributed to the deaths of individuals between 55 and 75 years old.
- 30.2% to younger than 55 and 25% to those older than 75.
Therefore, the average figure of 16 year lives lost includes the years lost from individuals close to the end of their expected lives but the majority of those years are from individuals with a significant remaining life expectancy.
In the higher income countries, a larger proportion of the year’s life lost is borne by the oldest group compared to the youngest groups.
The opposite pattern appears in low and mid income countries where a large fraction of the year lives lost are from individuals dying at ages 55 or younger.
If one looks at gender, men have lost 44% more years than women. Two causes appear to directly affect this disparity:
- A higher average age at death of female COVID-19 deaths, 71.3 for males, 75.9 for females resulting in a relatively lower years’ life loss per death 15.7 for males and 15.1 for females.
- More male deaths than female deaths in absolute numbers, 1.39 ratio of male to female deaths.
This study delivers three key insights:
- First, the total years’ lives lost as of January 6th 2021 is 20.507518 million, which in heavily affected countries is between two and nine times the median years’ lives lost of seasonal influenza or between a quarter and a half of heart disease. This implies 273,000 947 full lives lost or over 200,000 lives lived from birth to the average life expectancy of birth in our sample, 74.85 years.
- Second, three quarters of the years’ life lost are borne by people dying in ages below 75.
- Third, men have lost 45% more years of life than women.
These results confirm that the mortality impact of COVID-19 is large, not only terms of number of deaths but in terms of years of life lost.
Whilst the majority of deaths are occurring at ages above 75, justifying the policy responses aimed at protecting these vulnerable ages.
However, the results on age pattern call for a heightened awareness of devising policies to protect the young.
The gender differential in years of life lost arises from two components. More men are dying from COVID-19, but men are also dying at younger ages with more potential life years lost than women.
Holding the current age distribution of deaths constant, eliminating the gender differential in years’ life loss would require an average of 34% reduction in male death counts.
This suggests that gender specific policies might be equally well justified as those based on age.
Clearly this is an issue which all governments should consider when considering who should be vaccinated next.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed