That finding comes from a study showing that after age 55, even people with upper-middle-class incomes suffer more disability than those with even higher earnings.
Meredith Minkler, DrPH, and colleagues at the University of California, Berkeley, analyzed data from the 2000 U.S. Census. People below the poverty line for that year -- $17,761 for a family of four -- were six times more likely to suffer from a disability than those making seven times that much or more.
That's really no surprise. Poor people in the U.S. have limited access to health care. And they live and work in less healthy environments than wealthier Americans.
But Minkler and colleagues also found that people whose income was 600% of the poverty level were more likely to be disabled than those at 700% or higher.
The researchers defined disability as a condition lasting at least six months that made it difficult to dress, bathe, or get around the home.
"What was unusual was that we found that people in the middle class were still at a disadvantage compared with those at just a slightly higher income," Minkler said in a news release. "The fact that there's a significant difference between people at 600% and 700% above the poverty level was a striking finding of this study."
A four-person household at 600% of the year 2000 poverty level would have an income of $106,566 a year. The same household at 700% of the poverty level would earn $124,327 per year.
Men age 65-74 who earned between six and seven times the poverty level were 44% more likely to be disabled than those who earned seven or more times the poverty level.
"With almost 85% of Americans who are 55 years of age or older living at an income level under 700% of the poverty line, this is not simply an issue of very poor people having a disadvantage in health outcomes," Minkler and colleagues conclude. "Rather, higher risk is demonstrated across a very large proportion of the older population, as compared with the most advantaged."
The study appears in the Aug. 17 issue of The New England Journal of Medicine.
SOURCES: Minkler, M. The New England Journal of Medicine, Aug. 17, 2006; vol 355: pp 695-703. News release, University of California, Berkeley.
By Daniel DeNoon
Reviewed by Louise Chang