What Scientists Just Discovered About COVID-19’s Hidden Death Toll

COVID-19 didn’t just claim lives directly—it reshaped mortality patterns worldwide. A major international study found that life expectancy plummeted across most of the 24 analyzed countries, with additional deaths from cardiovascular disease, substance abuse, and mental health-related issues.

While some countries, like Japan and South Korea, fared better, Eastern Europe and the U.S. saw devastating losses. Interestingly, cancer mortality continued to decline, suggesting some medical services remained intact. The findings stress the urgent need for stronger healthcare systems to withstand future crises.

COVID-19’s Broad Impact on Global Mortality

A global study, co-authored by DPhil student Antonino Polizzi and Marie Sklodowska-Curie Fellow Dr. José Manuel Aburto, examined how the COVID-19 pandemic affected mortality across 24 countries.

Researchers from the University of Oxford, Australian National University, and the London School of Hygiene & Tropical Medicine analyzed cause-of-death data from these countries before and during the pandemic.

Staggering Declines in 2020 and 2021

Their findings revealed a sharp drop in life expectancy in 2020 for nearly all countries studied, with only four exceptions. The United States saw the steepest decline, with life expectancy for males falling by 2.1 years.

In 2021, life expectancy continued to decline in most countries. The most severe losses were recorded in Bulgaria for females and Latvia for males, both experiencing declines of more than two years.

COVID-19’s Lasting Mortality Effects

Lead author Antonino Polizzi 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.

Eastern Europe Hit Hard by Heart Disease

In 2020, cardiovascular disease-related losses were greatest in Russia which experienced losses of 5.3 months, while 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.

Substance Abuse and Mental Health Toll

The study also found increased mortality from substance abuse and mental health-related causes in some countries during the pandemic. The USA 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.

East Asia’s Resilience Amid the Crisis

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.

Lessons for the Future of Global Healthcare

The study concludes by underscoring the need for robust healthcare 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.

Dr. José Manuel Aburto said, “This study highlights the extent to which the COVID-19 pandemic impacted other causes of death, and the need to analyze different diseases and causes of death in a post-pandemic context to identify factors that can improve global healthcare systems.”

Reference: “Indirect effects of the COVID-19 pandemic: A cause-of-death analysis of life expectancy changes in 24 countries, 2015 to 2022” by Antonino Polizzi, Luyin Zhang, Sergey Timonin, Aashish Gupta, Jennifer Beam Dowd, David A Leon and José Manuel Aburto, 19 December 2024, PNAS Nexus.
DOI: 10.1093/pnasnexus/pgae508