Researchers estimated 12.7 million US deaths could have been averted between 1999–2022, when measured against the mortality rates of other high-income countries during that time. Photo by MarcBruxelle/iStock

Excess Deaths

Why Does the US Have Higher Death Rates than Other Wealthy Nations?

New Boston University study tracks America’s avoidable “excess deaths” and pinpoints major causes

The United States has the biggest economy in the world, spends more per person on healthcare than any other nation, and is home to three of the planet’s top-five hospitals. And yet it has a persistently lower life expectancy than other wealthy nations.

A new Boston University study puts a number on just how many additional deaths the US has had over the last two decades compared to its peer countries—and pinpoints some of the leading causes.

Published in JAMA Network Open, the study found that, between 1999–2022, annual excess US deaths—deaths that would not have occurred had the mortality rate been the same as other high-income countries (HICs)—increased steadily through 2019 and then rose rapidly during the COVID-19 pandemic. By 2022, all-cause mortality rates in America were 38 percent higher than in other HICs. An estimated 12.7 million US deaths could have been averted during this period, if US mortality rates mirrored those of its peers. The authors refer to these excess US deaths as “missing Americans.”

The BU team found that cardiovascular diseases, including heart disease, hypertension, and stroke, were the leading cause of excess mortality nearly every year. Together, cardiovascular and metabolic diseases accounted for over half of all excess US deaths in 2022. Drug poisonings, alcohol-related diseases, and suicides emerged as another major cause of excess mortality, particularly among men and people under 45 years old.

Homicide and HIV/AIDS also had mortality rates many times higher in the US than in other HICs; however, these causes were responsible for only a small share of excess US deaths. COVID-19 was a leading cause of US excess deaths from 2020–2022, representing roughly one in five US excess deaths in 2020 and 2021, and also coinciding with sharp increases in other diseases.

The study builds upon previous findings by the researchers that showed excess US deaths have increased since 1980 and continued to increase even after the COVID-19 pandemic.

“In public health, we know that death certificates only list the most proximate cause of death and not the full causal chain. Differences in social factors between the US and other HICs can lead to differences in behavioral risk factors, which in turn can lead to higher risks of specific causes of death,” says Jacob Bor, a BU School of Public Health associate professor of global health and epidemiology. “These findings pinpoint the issues that we should be focusing on if we want to address the US mortality disadvantage relative to peer countries.”

Previous studies have pointed to Americans’ comparatively poor health at birth, racial disparities, barriers to care, and obesity as important differences with other nations.

Bor and colleagues from BU, Harvard Medical School, and Hunter College at the City University of New York used cause-of-death data from the World Health Organization Mortality Database, comparing the US and 17 other countries, including Australia, Canada, France, Japan, and the United Kingdom.

“In US population health research, examining the stagnation in US life expectancy that began in 2010 usually focuses on drug overdoses, alcohol-related deaths, and suicide, known as ‘deaths of despair,’” says Andrew Stokes, an SPH associate professor of global health. “One dramatic finding from this study is that on an absolute scale, cardiometabolic diseases are key contributors to the increase in US death rates. If there was one thing we could address on a population scale, tackling cardiometabolic diseases would substantially reduce the US mortality gap with other wealthy nations.”

Drug poisonings are still a critical component of the US excess death conversation, the researchers note, particularly in terms of years of life lost, a measure that focuses on premature deaths and captures the societal burden of losing young people. These deaths represented the fastest increase in excess US deaths, rising from a near-equivalent level with peer countries in 1999 to more than 130,000 excess deaths in 2022, with a particular rise in 2013, after fentanyl entered the US drug supply.

The US did outperform peer countries in a couple of categories, comprising fewer excess deaths in 2022 for cancers (excluding lung cancer) and influenza, which Stokes attributes partly to advancements within the US healthcare system. “We’ve come a long way with medical innovations to screen and treat cancers,” he says.

The team says that more research is needed to understand the sharp rise in excess US deaths after 2010. But federal policy changes that address the root causes of these excess deaths and provide evidence-based interventions, the researchers say, would help alleviate the current national mortality burden.

“While new therapeutics such as GLP-1s could make a major dent in cardiometabolic mortality, our findings suggest that other policies should be considered too,” says Bor. “Countries that have the same, or even worse, access to advanced medical technology perform far better on these metrics than the US. We need to identify the policies that other countries have implemented, and think about how we can emulate those policies in the US.”

This study was supported by a grant from the W. K. Kellogg Foundation.