A recent study analyzing decades of data has revealed wide gaps in life expectancy in the U.S. due to differences in time and place of birth. Using data covering more than 50 years and 179 million deaths, researchers employed an age-period-cohort model to calculate period and cohort life expectancy for each of the 50 states and Washington, D.C. The results showed a notable increase in comparative longevity in some states, especially in the Northeast and West, while many Southern states have fallen significantly behind, especially among women.
This retrospective study, performed under the guidance of Yale University’s Institutional Review Board and utilizing public data from the CDC’s National Center for Health Statistics, examined mortality rates over the last 50 years (1969-2020). It used advanced statistical methods to identify the association of mortality trends that varied by age, period (calendar year), and birth cohort. The researchers could consider lifetime health exposures instead of collecting snapshots of health conditions at given times.
Despite an increase in life expectancy at the national level over the 20th century, the results demonstrate that these improvements were not distributed equally. Hawaii was the leading state in period life expectancy for females in 2020, with 84.5 years, while Mississippi had the lowest at 75.6 years. Among men, Washington, D.C. showed notable results improved from 62.7 years in 1969 to 72.8 years in 2020. In contrast, Southern states such as Mississippi and Louisiana showed continuously reported poor male life expectancy, and men born in Mississippi in 2020 were projected to live only 68.9 years.
From a cohort perspective (life expectancy tracked by year of birth), the gap was even greater. In New York and California, cohort life expectancy on average exceeded 91 years for females born in 2000, and 87.8 years for males. In the meantime, eight states in the South—Alabama, Kentucky, and West Virginia among them stayed at the bottom for both sexes.
In Washington, D.C, there were dramatic improvements. The female cohort life expectancy increased from 63.9 years recorded in 1900 to 93 years in 2000, while male expectancy increased from 48.7 to 86.5 years. Most of these changes are attributed to urbanization, better access to healthcare, and shifts in demography like gentrification. The study also examined the rate at which mortality risk rises with age, also called the mortality doubling time. Washington D.C remained again exceptional from slow aging rates-15.6 years for males and 12.3 years for females, with faster rates in states such as Oklahoma or Iowa. Higher life expectancy was positively linked with longer doubling times, indicating slower biological aging in attractive locations.
These findings strongly indicate that state-level policy has direct effects on longevity outcomes. For example, California’s early and aggressive anti-smoking campaign dramatically reduced deaths from tobacco. Instead, states like Kentucky and others continued to report high levels of smoking because there were few public health interventions.
Socioeconomic status also played a critical role. Rich and more urban states introduced wider health schemes, benefited from enhanced education, improved infrastructure, and increased access to medical services. These advantages led to extreme differences in the aging and survival of different generations.
The cohort-based method employed in the study provides a more nuanced insight into the issue of health inequalities, compared to traditional methods. With generational patterns, the policymakers are able to forecast the health needs and distribute resources efficiently.
The findings establish a base for subsequent simulations regarding the possible impacts of policy shuffles, shifts in economic circumstances, and health interventions. They also provide an essential tool for tracking whether the state disparity is narrowing or widening for newer birth cohorts.
This study highlights the urgent need to mitigate regional disparities in mortality. By knowing the way past policy choices influenced contemporary health results, the leaders will be able to shape more equitable public health procedures in the future.
References: Holford TR, McKay L, Tam J, Jeon J, Meza R. All-cause mortality and life expectancy by birth cohort across US states. JAMA Netw Open. 2025;8(4):e257695. doi:10.1001/jamanetworkopen.2025.7695
