New research has uncovered dramatic disparities in life expectancy — as much as 20 years — between counties with the lowest and highest life expectancies in the U.S., according to an article published JAMA Internal Medicine.
Christopher J.L. Murray, MD, DPhil, of the University of Washington in Seattle and his co-authors used population-based analysis to create annual estimates of life expectancy and age-specific risk of death for each county of the U.S. from 1980 to 2014. The authors included geographic inequalities, socioeconomic and race/ethnicity factors, as well as behavioral and metabolic risk factors, in their analysis.
Here are seven main findings from the report.
1. Between 1980 and 2014, life expectancy increased for men and women from 73.8 years to 79.1 years, respectively. Life expectancy increased from 70 to 76.7 years for men and from 77.5 to 81.5 years for women.
2. The gap between the counties with the highest and lowest life expectancies was 20.1 years. People in counties with the highest life spans tended to live to about 87, while those in counties with the lowest life spans died by about age 67, according to NPR. Dr. Murray told NPR the disparity in life expectancy across counties in the U.S. is comparable to low-income parts of the developing world and countries with advanced economies.
3. Several counties in South and North Dakota — especially those with Native American reservations — have the lowest life expectancies. Counties with the lowest life spans tend to include poor communities with less-educated people. The lowest life expectancy is in Oglala Lakota County, S.D., which houses the Pine Ridge Reservation, according to NPR.
4. Other counties with the shortest life expectancies are along the lower Mississippi River Valley and parts of West Virginia and Kentucky, NPR reported.
5. The counties with the longest life expectancy are more affluent and educated, such as Marin County, Calif., — which includes San Francisco — and Summit County, Colo., which houses Breckenridge.
6. Although life expectancy grew overall for each of the sexes individually and combined, there was significant variation at the county level. Socioeconomic and race/ethnicity factors (60 percent), behavioral and metabolic risk factors (74 percent) and healthcare factors (27 percent) accounted for this county-level variation. Combined, these factors explained 74 percent of county-level variation.
7. Dr. Murray's research suggests the gap isn't closing. In fact, it seems to be widening. The gap between the highest and lowest life expectancies by county increased by about two years between 1980 and 2014, according to the report.
"With every passing year, inequality — however you measure it — has been widening over the last 34 years," Dr. Murray told NPR. "And so next year, we can reliably expect it'll be even more than 20. That is probably the most alarming part of the analysis."