The current health of a population can be measured by life expectancy (LE). Increasing mortality within a population results in a decline in LE, while LE increases with a decrease in mortality. During the second half of the 20th century, significant increases in LE were observed in most countries. However, many of the more affluent countries experienced a slowing of LE improvement at the turn of the 21st century, before the coronavirus disease 2019 (COVID-19) pandemic.
The COVID-19 crisis created a mortality shock, leading to LE decreases in 2020 unprecedented in high-income nations today. While data constraints have prevented in-depth evaluations in low-to-middle-income nations, accumulating evidence suggests that losses in low-to-middle-income countries, such as India and Latin America, are considerably worse. Only a few nations, notably Norway, Denmark, females in Finland, New Zealand, and Australia, did not see LE drop in 2020.
In a recent study published on the preprint server medRxiv*, researchers investigated LE in 29 countries, including most European countries, Chile, and the USA, in 2021. The authors utilized data on all-cause mortality from the Short-Term Fluctuations Database (STMF). Decomposition techniques were used to describe which age groups and to what extent registered COVID-19 deaths contributed to recent trends and decreases in LE.
The authors compared the current global life expectancy decline and duration to notable mortality shocks in the twentieth century. The findings are broken down into three categories: females, males, and the entire population. They also look into the relationship between changes in life expectancy and vaccination uptake. These findings estimate COVID-19’s death load in 2021 and contribute to the discussion of current changes in life expectancy from a global viewpoint.
LE changes since 2019
Thirteen of the 29 nations studied saw LE recover from 2020 losses, while eleven observed losses continue. In the United States, Scotland, and Northern Ireland, LE stayed at the same low levels as in 2020, showing a persistent increase in mortality. Bulgaria, with record compound LE losses in 2020 and 2021, and Switzerland, with a record LE bounce-back, are at the extremes. Only three countries studied experienced no loss of LE in 2020, Finland, Denmark, and Norway, with Norway showing a significantly increased LE in 2021, compared to 2019.
In 2020, Bulgaria saw a 17.8-month drop in LE. This significant fall was exacerbated by a 24.6-month drop underneath the 2020 level in 2021, giving the country a net LE loss of 42.4 months since 2019. Bulgaria is the most extreme case among the nine previously Eastern Bloc countries. Every one of these countries, apart from Slovenia, experienced compound LE losses in 2021. Estonia had the third-highest LE losses in 2021 but virtually no losses in 2020. Chile and Greece both saw significant cumulative losses.
In all the studied countries in 2021, COVID-19-related deaths account for the LE decrease. Greece and the Netherlands were exceptions because more than half the deaths contributing to LE decline were not related to COVID-19. Individuals of the age group 60-79 contributed more towards the decline in LE in most countries, apart from Germany and Scotland.
LE deficit by vaccine uptake
In all nations, increased vaccination rates until October 2021 were linked to lower LE deficits in 2021. Eastern Europe, particularly Bulgaria, which had reduced vaccination uptake, had higher LE deficits, but other Central and Western European countries had the reverse problem. When evaluating the contributions of the age groups 60 and 60+ to the LE decline in 2021, the trend in the association was similar, while the strength of the association varied. Vaccination uptake was found to be more closely linked to LE decline in those aged 60 and up.
There is a likely complicated relationship between vaccination uptake and LE losses, as evidenced by notable anomalies. Compared to nations with similar average vaccination rates, such as the Netherlands or Switzerland, the United States had a much greater LE decline among individuals younger than 60 years.
The data highlighted Chile and Slovakia as nations with unusually substantial LE decline for people aged 60 and over, considering their vaccine rates. Some of these disparities could be explained by finer specifics of vaccination roll-out timing and age prioritizing, as well as relationships among vaccine uptake and adherence with non-pharmaceutical measures.
Implications
The influence of the pandemic on population health began to diverge in 2021. Some countries observed bounce-backs from a declining LE due to pharmaceutical and non-pharmaceutical measures, while others experienced a sustain in LE decline. Despite repeated mortality crises in the twentieth century, life expectancy continued to rise worldwide in the medium and long term, particularly in the second half of the century. While the COVID-19 pandemic has been the most significant global mortality shock since World War II, the long-term effects on LE are not yet fully determined.
*Important notice
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
