Researchers have analysed cause-of-death data for 24 countries before and during the COVID-19 pandemic. The researchers found that life expectancy declined in 2020 for all but four of the 24 included countries, with the US experiencing the largest decline of 2.1 years for males. In 2021, most countries experienced further declines in life expectancy, with females in Bulgaria and males in Latvia experiencing the largest losses of over two years.

Lead author Antonino Polizzi, student at the Leverhulme Centre for Demographic Science, said, "This study explores the direct and indirect effects of the COVID-19 pandemic on mortality across the world and highlights that life expectancy losses had still not returned to pre-pandemic levels in several countries by 2022."

The study found that, in addition to COVID-19 deaths, increased mortality attributed to cardiovascular disease was a major contributor to life expectancy losses during the first two years of the pandemic, particularly in Russia and Eastern Europe. The paper, "Indirect Effects of the COVID-19 Pandemic: A Cause-of-Death Analysis of Life Expectancy Changes in 24 Countries, 2015 to 2022," is published in PNAS Nexus.

In 2020, cardiovascular disease-related losses were greatest in Russia, which experienced losses of 5.3 months. Bulgaria experienced cardiovascular disease-related losses of 5.5 months in 2021. The authors suggest that this could have been due to lapses in prevention or treatment of cardiovascular disease, or undercounted COVID-19 deaths.

Co-author Professor Jennifer Dowd, Deputy Director of the Leverhulme Centre for Demographic Science and Oxford Population Health's Demographic Science Unit, said, "The pandemic reversed years of progress in reducing cardiovascular deaths in several countries, which constituted one of the largest sources of gains in life expectancy over the period 2015–2019. These losses continued through 2022."

The study also found increased mortality from substance abuse and mental health-related causes in some countries during the pandemic. The U.S. and Canada saw continued increases in drug-related deaths, contributing to life expectancy declines. Alcohol-related mortality also increased, with Latvia experiencing significant life expectancy losses. However, suicide and accident mortality typically declined during the pandemic years.

Japan and South Korea experienced minimal life expectancy losses during the pandemic and were the exception to most of these trends. However, females in Japan saw comparatively large losses from suicide mortality in 2020.

More positively, cancer mortality generally continued to decline in most countries. The authors speculate that cancer care was less disrupted than expected during the pandemic, or that people with cancer were more susceptible to COVID-19 mortality which was then not counted as a cancer death.

The study concludes by underscoring the need for robust health care systems capable of handling crises without compromising care for other conditions. It also highlights the importance of targeted public health interventions to address the varied impacts across different countries and age groups.

Co-author Dr. José Manuel Aburto, demographer at the Leverhulme Centre for Demographic Science and London School of Hygiene & Tropical Medicine, said, "This study highlights the extent to which the COVID-19 pandemic impacted other causes of death, and the need to analyse different diseases and causes of death in a post-pandemic context to identify factors that can improve global health care systems."

More information: Antonino Polizzi et al, Indirect effects of the COVID-19 pandemic: A cause-of-death analysis of life expectancy changes in 24 countries, 2015 to 2022, PNAS Nexus (2024). DOI: 10.1093/pnasnexus/pgae508