Americans died at substantially higher rates than residents of other wealthy countries between 1999 and 2022, and cardiovascular disease was the single largest driver. That is the finding of a study led by researchers at Boston University School of Public Health and published in JAMA Network Open, which calculated how many US deaths would not have occurred had American mortality rates matched those of peer high-income countries. The answer: an estimated 12.7 million over the 24-year period, a group the authors call the "missing Americans."
Alzheimer's disease and related dementias appear in the study's short list of conditions responsible for the gap, alongside cardiovascular disease, metabolic diseases including diabetes, and drug and alcohol complications. Cardiovascular and metabolic disease together accounted for more than half of all excess US deaths in 2022. Drug poisonings, alcohol-related illness, and suicide made up another large share, concentrated among men and people under 45. Homicide and HIV/AIDS rates were many times higher in the US than in comparison countries but contributed only modestly to the overall total.
For anyone thinking about brain health, the grouping matters. The same cardiometabolic conditions that dominate this mortality gap - heart disease, hypertension, stroke, diabetes - are the conditions repeatedly linked to dementia risk, and they show up here as the diseases where the US falls furthest behind its peers despite comparable access to advanced medical technology. The gap widened steadily through 2019 before accelerating sharply during the COVID-19 pandemic, leaving all-cause US mortality 38 percent higher than in other high-income countries by 2022.
The authors frame the problem as one of policy rather than medicine alone, arguing that the underlying health, social, and economic conditions that raise Americans' risk of developing these diseases need to be addressed. That places the findings less in the realm of individual clinical decisions and more in the realm of population-level prevention - the same terrain where much of the current thinking about reducing dementia burden now sits.