US county-level study links poor sleep to reduced life expectancy

It is estimated that more than 10 million American adults consistently get less than seven hours of sleep every night. For long before there was any widespread understanding of the importance of adequate rest, public health officials around the country have been telling those at the state and federal levels that seven hours is not enough to provide necessary protection for their long-term health.

Lack of sufficient sleep has been associated with many chronic health problems, including heart disease, metabolic diseases, and increased odds of dying early for adults who do not have any diagnosed sleep disorders. In addition to smoking and not exercising being accepted as risk factors for reduced longer-term health, there have been no major studies performed by state or local public health agencies related to sleep.

Research from Oregon Health & Science University has changed this. They analyzed both sleep and life expectancy data at a county level across the United States. Their study, published in SLEEP Advances found insufficient sleep to be one of the most significant indicators of longevity in the U.S. The findings suggest that your sleep and the place where you sleep all contribute to differences in life expectancy among various geographical locations across the country.

The researchers wanted to answer this question: Do counties with greater levels of insufficient sleep experience lower average life expectancy compared to other counties where people get enough sleep to meet the recommended guidelines? To do so, they used data from the Centers for Disease Control and Prevention's Behavioral Risk Factor Surveillance System (BRFSS), a nationwide telephone survey conducted by state public health departments that gathers information about health behaviors and conditions on an annual basis.

The researchers reviewed the BRFSS data collected from 2019 to 2025 and analyzed the data from 3,141 counties in 50 states. They asked survey participants how many hours of sleep they normally get in a day.

People who get less than 7 hrs. of sleep will be classified as having insufficient sleep according to the national standard established by the American Academy of Sleep Medicine and the Sleep Research Society.

The researchers then assigned a percentage to each county for the number of its residents who are chronically getting too little sleep. The numbers were then compared to county-level life expectancy estimates to determine how the two measures corresponded to one another across the United States.

The statistical methods that were utilized by the team were built on statistical techniques and models utilizing historical data over the period of multiple years. This allowed the researchers to find trends within counties over the years, as well as compare counties within the same state with other counties in the same state. Researchers were able to include all counties, even when missing data was found.

To control for the other factors that were known to impact health and longevity, the primary analysis adjusted for variables including, but not limited to, smoking rates, physical inactivity, food insecurity, unemployment, health insurance coverage, education, social connections, and diabetes. Additionally, a second model adjusted for obesity, which is usually associated with chronic sleep deprivation, and may also impact how sleep affects health.

By accounting for these variables, the researchers hoped to isolate the unique effect of sleep on life expectancy.

The notable finding of the study was that in the majority of U.S. states, there was a strong correlation between the amount of sleep that an adult obtained and the average lifespan for adult residents of that state. Only three states did not have a significant correlation in 2025. In all other states, the association was strong and statistically significant.

This pattern continued over the years. Sleep has been shown as a significant factor in the prediction of life expectancies of people who have poor sleep habits. In 2019, 84% of the states surveyed demonstrated a strong correlation between the amount of sleep a person gets and their life expectancy. By 2024, all states surveyed demonstrated a similar correlation between sleep and life expectancy. Even during times of disruption, such as during the COVID-19 pandemic, the relationship between sleep and life expectancy remained constant.

In this multi-year study, sleep deprivation was identified as one of the top 5 predictors of premature death. It has an even larger effect on life expectancy than diet, physical activity, social isolation, and most of the other factors that influence health. Tobacco use is still the strongest predictor of premature death; however, sleep is close behind.

Andrew McHill, senior author of this report told The Brighter Side of News, "We didn’t realize sleep was so closely tied to life expectancy." He is an Assistant Professor at the Oregon Health Sciences University (OHSU) and a Senior Researcher at the OHSU Institute for Occupational Safety and Health. "Researchers in the field have long linked sleep loss to early death, but our newly shown county-level strength of that connection is especially notable."

Obesity and diabetes affect life expectancy by decreasing the effect of sleep deprivation on life expectancy. By adding obesity and diabetes into the model, the effect of insufficient sleep diminished slightly, but sleep still predicts shorter life expectancies even when obesity and diabetes are included. In the larger model presented herein, smoking and obesity had the most significant association with poor life expectancy.

These results surprised researchers in the field of sleep medicine. McHill pointed out that while scientists have been aware for some time that insufficient sleep increases mortality risk, the magnitude of the association at the county level is a unique and surprising finding.

“While it’s intuitive and makes a lot of sense, seeing it materialize so strongly across all these models remained eye-opening,” he said. “The strength of the association between sleep sufficiency and life expectancy was the most impressive part.”

The study was limited despite being so large. In addition, the BRFSS survey does not include information on shift workers, sleep disorders or sleep quality which has an impact on health. The number of hours a person sleeps over 7 hours of sleep was grouped with those who sleep only 7 hours, even though getting an excessive amount of sleep can be an indication of some type of health problems.

Another limitation of the study was the lack of direct measurement of dietary patterns. In this case, food insecurity was included; however, the results could not determine differences in nutrition that contribute to both sleep and longevity.

Nevertheless, according to the researchers, given the large and consistent size of the dataset, it is difficult to ignore the overarching conclusions.

According to the results of this study, not obtaining enough sleep is not just an individual issue, but rather a public health issue at the community level. High levels of short sleep in counties indicate that public health efforts targeted at individuals living in that community may have a significant impact.

“This study demonstrates there is a need to prioritize sleep as much as what we eat or how we exercise,” according to McHill. “Sometimes we think of sleep as something we will never get enough of. Getting enough sleep will help improve not only how you feel today, but also how long you live as well.”

The results of this study have identified sleep as a behavior that can be modified to promote the health of the population.

Local government officials, employers, and health care officials can use the results from this study to support sleep education, changes in the work schedules of employees, and programs that promote community-wide sleep health. In particular, by improving the sleep habits of people living in high-risk counties, communities can potentially improve quality of life and ultimately reduce early mortality.

For researchers, these findings are contributing to an expanded understanding of the ways in which sleep interacts with social, economic and environmental factors over time.

Research findings are available online in the journal SLEEP Advances.

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