Study examines trends in life expectancy in the U.S. at county level

Reviewed by Emily Henderson, B.Sc.Jun 16 2022

From 2000-2019 overall life expectancy in the United States increased by 2.3 years, but the increase was not consistent among racial and ethnic groups and by geographic area. In addition, most of these gains were prior to 2010. This is according to a new study funded by the National Institutes of Health that examined trends in life expectancy at the county level. The study was led by researchers at the Institute for Health Metrics and Evaluation at the University of Washington's School of Medicine, Seattle, in collaboration with researchers from NIH and published on June 16th in The Lancet.

These varied outcomes in life expectancy raise significant questions. Why is life expectancy worse for some and better for others? The novel details in this study provide us the opportunity to evaluate the impact of social and structural determinants on health outcomes in unprecedented ways. This in turn allows us to better identify responsive and enduring interventions for local communities."

Eliseo J. Pérez-Stable, M.D., co-author and director, National Institute on Minority Health and Health Disparities (NIMHD)

In most counties, life expectancy for the Black population has increased more than any other racial and ethnic group but overall, the Black population still has a lower life expectancy than the white population.  Meanwhile, the white population had a moderate increase, and in some counties, a decrease in life expectancy. Considering these two trends, the study noted that the decrease in the white-Black life expectancy gap could be attributed to the stagnation and reversal of gains in the white population. In addition, American Indian and Alaska Native populations have the lowest life expectancy of all populations and experienced a decrease in most counties, with a gap of more than 21 years in some counties.

At the same time, the Latino/Hispanic and Asian populations had the longest life expectancy at the national level, but this advantage was not observed in all counties. While these population groups maintained longer life expectancy than the white population, the advantage narrowed in a sizeable minority of counties for the Latino/Hispanic population (42%) and in most counties for the Asian population (60.2%). Life expectancy at the county level varied from 58.6 years for AIAN to 94.9 years for the Latino/Hispanic population, a range of 36 years.

Among the findings and trends:

National level

• In 2019, overall life expectancy in years was 85.7 for the Asian population, 82.2 for the Latino population, 78.9 for the white population, 75.3 for the Black population, and 73.1 for the AIAN population.
• Between 2000 and 2019, life expectancy increased most for the Black population (3.9 years), the Asian population (2.9 years), and the Latino population (2.7 years). At the same time, the increase in life expectancy for the white population was more moderate (1.7 years). For AIAN populations, there was no improvement in life expectancy.
• From 2010 to 2019, the Asian, Latino, Black, and white populations experienced only small improvements in life expectancy.

County level

• From 2000 to 2019, 88% of U.S. counties experienced an increase in life expectancy; however, most of these gains were from 2000-2010.
• Almost 60% of U.S. counties experienced a decrease in life expectancy from 2010 to 2019.
• In 2019, life expectancy varied widely among counties. For all groups combined, the estimated life expectancy was below 65 years in some counties and over 90 years in others. The range of life expectancy also varied within groups.
• For the AIAN population, the estimated life expectancy in different counties in 2019 ranged from under 59 to over 93 years.

This is the first U.S.-wide time-series analysis of life expectancy at the county level that includes estimates for the American Indian/Alaska Native (AIAN) and Asian populations as well as white, Black, and Latino/Hispanic populations. This is also the first county-level study that corrected misreporting of racial and ethnic identity on death records. Using novel small area estimation models, researchers analyzed death records from the National Vital Statistics System and population estimates from the National Center for Health Statistics, providing the most comprehensive data on life expectancy across 3,110 counties.

It is important to note that the study estimates for the Asian population do not separate the differences between Asian Americans and Native Hawaiian and Pacific Islanders (NHPI) populations. Researchers note that estimates for the Asian population likely masked important differences in life expectancy between these two populations. Previous regional studies generally show worse outcomes for NHPI populations, further underscoring the need to study these groups individually.

This study gives a detailed analysis of life expectancy two decades preceding the COVID-19 pandemic, providing context for changes to mortality and disparities that have occurred since the beginning of the pandemic. Provisional estimates for 2020 show substantial declines in life expectancy overall and for the Black, Latino, and white populations. These declines were larger for the Latino and Black populations than the white population, possibly reversing gains observed over the period of this study.

"The pandemic exposed stressors and weaknesses in local and national systems that continuously put our most vulnerable populations at risk. These findings offer county, state, and federal leaders a unique look at the pervasiveness of health disparities in their respective communities," said Laura Dwyer-Lindgren, Ph.D., lead author and assistant professor of health metrics at the Institute for Health Metrics and Evaluation.

George Mensah, MD, co-author, and director of the Center for Translation Research and Implementation Science at the National, Heart, Lung, and Blood Institute (NHLBI) noted that the findings should be an alarm bell to urgently address root causes to truly eliminate health disparities and at the same time, promote healthy living and longevity for everyone. "Researchers, policymakers, and thought leaders can all benefit from this study if we use the data to inform our actions, and this begins with active community engagement," he added.

Future researchers can use the data as a starting point for studying why the gaps in life expectancy vary so much between places. Possible reasons that previous research has found include county-level differences in income or education, exposure to environmental risks, and differences in the built environment.

The NIH co-authors of the study are members of the U.S. Burden of Health Disparities Working Group. They include NIMHD Director, Eliseo J. Pérez-Stable, M.D.; NIMHD Scientific Director Anna María Nápoles, Ph.D., M.P.H.; NHLBI Director of The Center for Translation Research and Implementation Science, George A. Mensah, M.D.; as well as researchers at the National Cancer Institute; National Institute on Aging; National Institute of Arthritis and Musculoskeletal and Skin Diseases; and the NIH Office of the Director.