Life expectancy has risen overall in the United States in recent decades, but at the county level, not everyone is benefiting equally, according to a study published Tuesday in JAMA Internal Medicine.
In fact, the gap between counties with the shortest and longest life expectancy at birth varied by 20 years in 2014 — a disparity that is larger than it was in 1980.
Oglala Dakota County in southwestern South Dakota, which includes the Pine Ridge Reservation, had the lowest life expectancy in the country in 2014 at 66.8 years. The county with the highest life expectancy — 86.8 years — was Summit County in Colorado, which includes several ski resorts.
“This study found large — and increasing — disparities among counties in life expectancy over the past 35 years,” the study’s authors conclude. “The magnitude of these disparities demands action, all the more urgently because inequalities will only increase further if recent trends are allowed to continue uncontested.”
Gains and losses
For the study, researchers at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington in Seattle used various national databases to estimate life expectancy for each county from 1980 to 2014.
During those 35 years, U.S. life expectancy at birth increased overall by 5.3 years for both men and women, from 73.8 years to 79.1 years. Men gained an average of 6.7 years, from 70 years to 76.7 years, while women gained an average of four years, from 77.5 years to 81.5 years.
But, as noted, those gains weren’t shared across the country. In fact, in 13 counties, newborn babies had shorter expected life spans in 2014 than their parents’ generation did at birth in 1980. In Owsley County, Kentucky, for example, the average life span in 2014 was 70.2, more than a two-year drop from 72.4 in 1980.
Counties with low life expectancies were particularly prevalent in Kentucky, West Virginia, Alabama and several states along the Mississippi River, the study found.
Counties that showed the greatest improvement in life expectancies since 1980 were in central Colorado, Alaska and along both the eastern and western coastlines.
Minnesota’s counties fell somewhere in between.
Age and other factors
The researchers also looked at the risk of dying among five age groups, as well as the extent to which risk factors, such as socioeconomics, race/ethnicity, health-related behaviors and access to health care, contribute to inequalities in life expectancy at the county level.
Between 1980 and 2014, all counties experienced declines in their rate of early death among children under the age of 5, and the gap between the counties with the highest and lowest early death rates for children in that age group narrowed. Almost all counties (more than 98 percent) also showed declines in the rate of early death in two other age groups: children and young adults aged 5 to 25 and middle-aged and older adults aged 45 to 85.
On the other hand, the risk of early death for people between the ages of 25 and 45 increased in 11.5 percent of the counties during the study period. Furthermore, inequities in the risk of dying early rose for all adults, although particularly for those age 65 to 85.
Behavioral and metabolic risk factors — such as smoking, obesity, lack of exercise, diabetes and high blood pressure — were associated with 74 percent of the variation in life expectancy, the study found. Socioeconomic factors such as income, education, unemployment and race were independently related to 60 percent of the variation. Health-care access and quality explained 27 percent of the inequities.
‘Not acceptable for a country like the U.S.’
“Looking at life expectancy on a national level masks the massive differences that exist at the local level, especially in a country as diverse as the United States,” said Laura Dwyer-Lindgren, an IHME researcher and the study’s lead author, in a released statement. “Risk factors like obesity, lack of exercise, high blood pressure, and smoking explain a large portion of the variation in lifespans, but so do socioeconomic factors like race, education, and income.”
“You expect disparities in any country, but you don’t expect the disparities to be increasing in a country with our wealth and might,” Mokdad said. “We spend more money on health care than anybody else, and we debate the hell out of health care more than anybody else, and still the disparities are increasing.”
“Everybody, in Europe and elsewhere, is increasing life expectancy at a greater pace than we are,” he added, “so that’s also disappointing and not acceptable for a country like the U.S. … I hope policymakers will look at this and say it’s not about politics any more, but the future of the United States.”
FMI: You can read the study in full at the JAMA Internal Medicine website. IHME has also posted an interactive map on its website, where you can explore county-level life expectancy trends in Minnesota and across the U.S..