What Accounts for the Rise in Excess U.S. Deaths Since 1999?

Bor et al. (2026) examined which causes of death account for the large number of excess deaths in the United States compared with 17 other high-income countries between 1999 and 2022. They analyzed more than 63.5 million U.S. deaths using mortality data from the World Health Organization Mortality Database. They found that the United States experienced about 12.7 million excess deaths during the study period, rising from 346,166 in 1999 to 905,159 in 2022. In 2022, circulatory diseases accounted for 40% of excess deaths (358,573 deaths), while drug poisonings, alcohol-related deaths, and suicide accounted for 131,151 excess deaths, or 14% of the total.

Why This Article Was Selected for The Policy Scientist

This article addresses an important policy question because mortality is one of the most comprehensive indicators of population well-being and reflects the cumulative effects of health, economic, and social institutions. The topic is especially timely given continuing concern about declining U.S. life expectancy and persistent mortality gaps relative to other high-income countries. Bor and colleagues have contributed extensively to this literature, including prior work on “Missing Americans,” and this study substantially extends that research by providing a comprehensive cause-specific analysis spanning more than two decades. The data are exceptionally strong, covering national mortality records across 18 countries. The findings are likely generalizable to other high-income nations. The statistical methods are rigorous and appropriate for descriptive population comparisons, although future research would be strengthened by causal inference approaches capable of identifying the specific mechanisms driving these mortality differences.

Full Citation and Link to Article

Bor, J., Raquib, R. V., Himmelstein, D., Woolhandler, S., & Stokes, A. C. (2026). Causes of excess deaths in the US compared with other high-income countries. JAMA Network Open, 9(5), e266147. https://doi.org/10.1001/jamanetworkopen.2026.6147

Central Research Question

This study investigates a straightforward but consequential question: which causes of death account for the large and growing number of excess deaths in the United States relative to other high-income countries, and how have those causes changed between 1999 and 2022? The authors define excess deaths as deaths that would not have occurred if Americans experienced the same age-specific mortality rates as residents of 17 comparable high-income countries. Rather than focusing on a single disease, age group, or year, the study provides a comprehensive assessment of mortality differences across all major causes of death over more than two decades. The authors also examine how these causes vary by age and sex and evaluate the contribution of each cause to excess years of life lost.

Previous Literature

The study builds upon a substantial literature documenting the decline of U.S. life expectancy relative to other affluent nations. Previous research has estimated millions of “missing Americans” who would still be alive if U.S. mortality rates matched those of peer countries. Other studies have examined particular explanations for the mortality gap, including cardiovascular disease, drug overdoses, deaths of despair, and COVID-19 mortality.

The authors note that earlier research generally focused on specific causes of death, selected age groups, single years, or a limited set of countries. As a result, the literature lacked a comprehensive accounting of all major causes contributing to excess mortality over time. This article seeks to fill that gap by conducting what the authors describe as a “population autopsy,” systematically identifying the causes responsible for the United States’ mortality disadvantage.

The study also connects to debates regarding whether cardiovascular disease or deaths of despair are the primary drivers of declining U.S. health outcomes. Rather than treating these explanations as competing theories, the authors demonstrate that both contribute substantially, although in different age groups and through different mechanisms.

Data

The analysis relies on exceptionally large and comprehensive mortality datasets. The authors use death records from the World Health Organization Mortality Database covering the years 1999 through 2022. Population estimates come from the Human Mortality Database. The comparison group consists of 17 high-income countries: Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Iceland, Italy, Japan, Luxembourg, the Netherlands, Spain, Sweden, Switzerland, and the United Kingdom.

Across the study period, the authors analyze more than 63.5 million deaths in the United States and more than 117 million deaths in the comparison countries. Nearly all deaths had valid cause-of-death information available for analysis. Causes of death were grouped into 17 mutually exclusive categories, including circulatory diseases, cancers, respiratory diseases, diabetes and metabolic diseases, drug poisonings, suicide, alcohol-related mortality, homicide, transportation accidents, COVID-19, and other causes.

The breadth of these data represents a major strength of the study. The datasets cover national populations rather than samples and provide more than two decades of comparable mortality information across numerous countries. This scope allows the authors to examine long-term trends that would be difficult to observe in smaller or shorter-duration studies.

Methods

The study employs a repeated cross-sectional design. For each age group, sex, year, and cause of death, the authors calculated mortality rates in the United States and compared them with the population-weighted average mortality rate of the 17 peer countries.

The analysis focuses on three principal measures. First, the authors calculate excess deaths, defined as the difference between observed U.S. deaths and the number expected if U.S. mortality rates matched those of peer countries. Second, they calculate excess years of life lost (YLL), which gives greater weight to deaths occurring at younger ages. Third, they compute mortality rate ratios comparing U.S. death rates with those of other high-income countries.

The authors also conduct joinpoint regression analyses to identify changes in mortality trends over time and estimate deviations from pre-pandemic trajectories during the COVID-19 period. These methods are well suited to descriptive population analysis and trend identification.

However, the study remains fundamentally descriptive rather than causal. While the authors identify which causes contribute most to excess mortality, the analysis cannot definitively establish why those mortality differences exist. Future research employing causal inference methods, natural experiments, or other quasi-experimental approaches could strengthen understanding of the specific policies and social conditions responsible for these mortality gaps.

Findings/Size Effects

The findings reveal a substantial and growing mortality disadvantage for the United States. Between 1999 and 2022, the United States experienced approximately 12.7 million excess deaths and more than 314 million excess years of life lost compared with peer countries.

Annual excess deaths increased dramatically during the study period. In 1999, the United States recorded 346,166 excess deaths. By 2019, that figure had risen to 636,306. During the COVID-19 pandemic, excess deaths exceeded one million in both 2020 and 2021 before declining to 905,159 in 2022. By the end of the study period, overall mortality rates in the United States were 38 percent higher than those observed in comparable high-income countries.

Circulatory diseases emerged as the leading contributor to excess mortality. In 2022 alone, circulatory diseases accounted for 358,573 excess deaths, representing approximately 40 percent of all excess deaths. When combined with diabetes, kidney, and metabolic diseases, these conditions accounted for more than half of all excess deaths in 2022.

Mental and nervous system disorders constituted the second-largest contributor, accounting for 179,116 excess deaths in 2022. Diabetes, kidney, and metabolic diseases accounted for an additional 114,538 excess deaths.

Drug poisonings represented one of the most striking findings. Drug poisoning deaths were 7.48 times higher in the United States than in peer countries. In 2022, drug poisonings accounted for 93,504 excess deaths. When combined with alcohol-related deaths and suicide, these causes produced 131,151 excess deaths. Collectively, they accounted for approximately 24 percent of the overall increase in excess mortality between 1999 and 2022.

The age distribution of excess deaths is particularly informative. Among younger Americans, especially those aged 0 to 44 years, drug poisonings, alcohol-related mortality, and suicide accounted for most of the increase in excess mortality. In contrast, among older adults, circulatory disease and metabolic conditions were the primary contributors.

The study also highlights differences between absolute and relative mortality gaps. Homicide mortality rates were more than 14 times higher in the United States than in peer countries, and HIV/AIDS mortality rates were more than six times higher. However, because these causes account for relatively few deaths overall, their contribution to total excess mortality was smaller than that of circulatory disease.

COVID-19 contributed substantially to excess mortality during the pandemic years. In 2020 and 2021, COVID-19 accounted for approximately one-fifth of all excess deaths. Importantly, the pandemic also coincided with increases in excess mortality from circulatory disease, metabolic conditions, drug poisonings, alcohol-related deaths, and suicide.

Conclusion

The authors conclude that the United States has experienced persistently higher mortality than comparable high-income countries despite similar access to advanced medical technologies. The growth in excess mortality reflects two dominant patterns. First, deaths associated with drug poisonings, alcohol, and suicide increased rapidly, particularly among younger adults. Second, excess mortality from circulatory and metabolic diseases increased steadily among middle-aged and older adults.

The study provides the most comprehensive assessment to date of the causes underlying excess U.S. mortality over the last quarter century. By documenting both the magnitude and composition of excess deaths, the analysis clarifies how different causes contribute to mortality divergence across age groups and time periods. Although the study does not identify the causal mechanisms responsible for these trends, it establishes an important empirical foundation for future research examining the health, economic, and social factors associated with the United States’ growing mortality disadvantage.