Sept. 13, 2006
 
HEALTH: Where You Live Might Dictate How Long You Live
 
By Lee Bowman
Scripps Howard News Service
 
The "longevity gap" between residents of some U.S. counties is as wide as those seen between the world's most-advanced and least-developed nations, according to a new study by researchers at Harvard University.
 
At the high end are Asian-American women living in Bergen County, N.J., who have an average life span of 91 years, while Native American men and women living in and around two reservations in southwest South Dakota have an average life expectancy of 58 years.
 
Only a few hundred miles separate those South Dakota counties in and around the Pine Ridge and Rosebud reservations and a cluster of Front Range counties west of Denver. But the overall life expectancy in the South Dakota counties is 66.6 years, while the combined life expectancy for Clear Creek, Eagle, Gilpin, Grand, Jackson, Park and Summit counties in Colorado is 81.3 years.
 
The life-expectancy gap between the longest- and shortest-lived counties has been rising since the mid-1980s, said Dr. Christopher Murray, director of the Harvard Initiative for Global Health and lead author of the report, published online Monday by the Public Library of Science journal Medicine. "The counties that started out best just keep getting better. Those at the bottom stayed the same or got worse," Murray said.
 
The researchers did their analysis of life span at the state and county level across the United States using data collected between 1980 and 2000 by the Census Bureau and the National Center for Health Statistics.
 
The study concludes that, not counting the 214 million middle-income Americans (average per capita income of $24,640), there are at least seven clusters of people defined by geography and race who have life expectancies well above or below the norm.
 
"What's really striking is that the disparities are greatest in young and middle-aged people, which has traditionally been groups that we haven't spent much time worrying about," Murray said. "Yet we're seeing mortality levels in some subgroups of this segment in the U.S. that resemble those of some countries in West Africa."
 
Typically, researchers have focused on income, infant mortality, violence, AIDS and lack of health insurance to explain differences in mortality. But Murray said those factors account for only a small fraction of the variations his team found.
 
For instance, low-income, rural white populations in 112 counties in Minnesota, Iowa, Montana, Nebraska and the Dakotas -- what the researchers term the Northland -- have a life expectancy of 76.2 years for men and 81.8 years for women. Together, those numbers are well above the remaining white population in the country, which has a combined life expectancy of 77.1 years.
 
"Something very geographic is going on, but typical analytic methods miss that part of the study because researchers rarely look at place. Some really interesting patterns aren't related to the usual factors. It is not simply income and race. Perhaps it is shared ancestry or the way people make a living or cultural traditions in how they eat or exercise. The tricky part is figuring out what it is," Murray said.
 
Given that rural poor people generally don't have great access to health care or insurance, "it's unlikely that formal health care is much of a factor in the longevity difference for the Northland group."
 
Instead, chronic diseases such as heart disease and cancer, and injuries from well-established risks, such as alcohol-related traffic accidents, appeared to make the most difference.
 
"The good news is that we have relatively cheap, effective strategies for addressing a lot of contributors to chronic illness like lowering blood pressure and cholesterol levels with lifestyle changes and medication. Our hope is that this research will help policymakers better target these interventions for groups of young and middle-aged adults most at risk," Murray said.
 
Among the states, Hawaii has the greatest combined life expectancy, 80 years, although the advantage is somewhat of a statistical blip because the state is so small. Other healthy states in which the combined life expectancy tops 78 years are California, Colorado, Connecticut, Massachusetts, Minnesota, North Dakota, New Hampshire, Vermont and Washington.
 
Partially due to its small size and "city-state" status, the District of Columbia ranks as the unhealthiest jurisdiction in which to live, with a combined life expectancy of 72 years, followed by Mississippi with 73.6 years; Louisiana, 74.2 years; Alabama, 74.4 years and South Carolina, 74.8 years.
 
A complete set of county data on life expectancy for both males and females can be found at http://www.globalhealth.Harvard.edu
 
Or http://medicine.plosjournals.org
 
Contact Lee Bowman at BowmanL@SHNS.com. Distributed by Scripps Howard News Service, http://www.shns.com