Research press release


Nature Medicine

Epidemiology: COVID-19 death toll reduces life expectancy in Brazil

ブラジルでは、新型コロナウイルス感染症(COVID-19)が原因の死亡者数によって、2020年の出生時平均余命(平均寿命)は1.3年、2021年1月から4月では1.8年短くなったことが、Nature Medicine に掲載される研究で明らかになった。一部の州では、COVID-19に遭遇したことで、平均余命がこの20年では見られなかったほど短くなっており、最も大幅な短縮は2020年のアマゾナス州の3.46年である。


COVID-19関連死がブラジルの人口に及ぼす影響を数値化しようと、Marcia Castroたちは2020年1月から2021年4月にかけて報告された全死亡者数のデータを解析して、各州の死亡者数を調べた。著者たちは、2019年と2020年にブラジルで報告された総死亡者数に基づいて、出生時平均余命が1.31年短くなったと推定した。落ち込み幅は、女性(0.95年)よりも男性(1.57年)の方が大きかった。65歳の平均余命は0.94年短くなったと推定された。2021年1月1日から4月25日までの期間では、出生時平均余命が1.78年、65歳の平均余命は1.05年短くなった。平均すると、出生時平均余命、65歳の平均余命の落ち込み幅は、2020年、2021年共にブラジル北部地域でより大きいことが分かった。北部地域は、所得格差、貧困、インフラへのアクセス、医師数、利用可能な病床数という指標のいくつかが最悪の値であり、また感染制御対策が(たとえば北東部に比べ)それほど厳格に実施されていなかった。


The total reported deaths caused by COVID-19 in Brazil reduced life expectancy at birth by 1.3 years in 2020 and by 1.8 years from January to April 2021, according to a paper published in Nature Medicine. In some states, life expectancy in the face of COVID-19 has been reduced to levels not seen in 20 years, with the greatest drop being 3.46 years in Amazonas state in 2020.

April 2021 was the deadliest month since the pandemic began in Brazil: nine capital cities reported more deaths than births. The consequences of that death toll can be measured by life expectancy at birth, which indicates the average number of years a newborn would be expected to live if born in a specific year, given the prevailing mortality rates in that year throughout life. As the risk of dying from COVID-19 is greater at older ages, the death toll can also be reflected by considering changes in life expectancy at age 65—the number of years a person would be expected to live if they continued to be subject to the underlying mortality rates for ages 65 and above of a specific year.

To quantify the consequences of COVID-19-related deaths on the population of Brazil, Marcia Castro and colleagues analyzed data on reported total deaths in 2020 and from January through April 2021 to measure the death toll across states. On the basis of the total number of deaths reported in Brazil in 2019 and 2020, the authors estimated a reduction of life expectancy at birth of 1.31 years, with a larger drop for males (1.57 years) than for females (0.95 years). The estimated decrease in life expectancy at age 65 was 0.94 years. In 2021, from 1 January to 25 April, the life expectancy at birth fell by 1.78 years, and life expectancy at 65 fell by 1.05 years. On average, the authors observed larger decreases in life expectancy at birth and at age 65 in the North region of Brazil, both in 2020 and 2021. This region has some of the worst indicators of income inequality, poverty, access to infrastructure and availability of physicians and hospital beds, and was less stringent in the implementation of control policies (compared to the Northeast region, for example).

The authors argue that without immediate changes to the pandemic response and to testing and vaccination availability, life expectancy will not rebound quickly, as has been seen historically elsewhere after intense shocks such as a pandemic or wars. They predict that the future demographic consequences for Brazil may be even more severe than those reported in their findings.

doi: 10.1038/s41591-021-01437-z


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