WASHINGTON — New government research has found "large and growing" disparities in life expectancy for richer and poorer Americans, paralleling the growth of income inequality in the last two decades.
Life expectancy for the nation as a whole has increased, the researchers said, but affluent people have experienced greater gains, and this, in turn, has caused a widening gap.
One of the researchers, Gopal Singh, a demographer at the Department of Health and Human Services, said "the growing inequalities in life expectancy" mirror trends in infant mortality and in death from heart disease and certain cancers.
The gaps have been increasing despite efforts by the federal government to reduce them. One of the top goals of "Healthy People 2010," an official statement of national health objectives issued in 2000, is to "eliminate health disparities among different segments of the population," including higher- and lower-income groups and people of different racial and ethnic backgrounds.
Singh said last week that federal officials had found "widening socioeconomic inequalities in life expectancy" at birth and at every age level.
He and another researcher, Mohammad Siahpush, a professor at the University of Nebraska Medical Center in Omaha, developed an index to measure social and economic conditions in every county, using census data on education, income, poverty, housing and other factors. Counties were then classified into 10 groups of equal population size.
In 1980-82, Singh said, people in the most affluent group could expect to live 2.8 years longer than people in the most deprived group (75.8 vs. 73 years). By 1998-2000, the difference in life expectancy had increased to 4.5 years (79.2 vs. 74.7 years), and it continues to grow, he said.
After 20 years, the lowest socioeconomic group lagged further behind the most affluent, Singh said, noting that "life expectancy was higher for the most affluent in 1980 than for the most deprived group in 2000."
"If you look at the extremes in 2000," Singh said, "men in the most deprived counties had 10 years' shorter life expectancy than women in the most affluent counties." The difference between poor black men and affluent white women was more than 14 years.
The Democratic candidates for president, Sens. Hillary Rodham Clinton, D-N.Y., and Barack Obama, D-Ill., have championed legislation to reduce such disparities, as have some Republicans, like Sen. Thad Cochran of Mississippi.
Peter Orszag, director of the Congressional Budget Office, said: "We have heard a lot about growing income inequality. There has been much less attention paid to growing inequality in life expectancy, which is really quite dramatic."
While researchers do not agree on an explanation for the widening gap, they have suggested many reasons, including:
• Doctors can detect and treat many forms of cancer and heart disease because of advances in medical science and technology. People who are affluent and better educated are more likely to take advantage of these discoveries.
• Smoking has declined more rapidly among people with greater education and income.
• Lower-income people are more likely to live in unsafe neighborhoods, to engage in risky or unhealthy behavior and to eat unhealthy food.
• Lower-income people are less likely to have health insurance, so they are less likely to receive checkups, screenings, diagnostic tests, prescription drugs and other types of care.
Even among people who have insurance, many studies have documented racial disparities.
In a recent report, the Department of Veterans Affairs found that black patients "tend to receive less aggressive medical care than whites" at its hospitals and clinics.