Low-income Americans ages 55 to 84 are far more likely than their
wealthier peers to feel limited in doing basic physical activities
such as climbing stairs and lifting objects, according to a new
study. The research, published in the August 17, 2006, issue of The
New England Journal of Medicine, shows, for example, that
people ages 55 to 64 who are living below the poverty line are
six times more likely than the wealthiest group to say they have
functional limitations.
The study was conducted by the National Institute on Aging (NIA),
part of the National Institutes of Health, in collaboration with
the University of California, Berkeley, and the University of Toronto.
The researchers report that those living below the poverty line
are the most likely to say they have functional limitations, and,
up to age 84, the odds of having such limitations drops with each
incremental increase in income. They also note that older people
are less likely to report functional limitations with each increase
in educational level, a measure that is closely tied to income.
"We found that a 'gradient of disability' exists across the full
socioeconomic spectrum, as functional limitations proved inversely
related to household income," says senior author Jack M. Guralnik,
M.D., Ph.D., chief of the NIA?s Laboratory of Epidemiology, Demography
and Biometry.
Improved understanding of the relationship between socioeconomic
status and disability is critical as the U.S. population ages,
Guralnik notes. The rate of disability decreased 1 to 2 percent
annually during the 1980s and 1990s, when trends were last reported,
and the rate of decline was smaller among those in the poorest
socioeconomic groups.
Guralnik and co-authors Meredith Minkler, D.P.H., University of
California, Berkeley, and Esme Fuller-Thomson, Ph.D., University
of Toronto, analyzed data for more than 335,000 community-dwelling
people 55 and older who participated in the Census 2000 Supplementary
Survey. Nearly one in four respondents reported having a functional
limitation, defined as a long-lasting condition that substantially
limits one or more basic physical activities, such as walking,
climbing stairs, reaching, lifting or carrying.
Functional limitation differences by income level were evident
among those 55 to 64 years, 65 to 74 years, and 75 to 84 years,
but differed more dramatically in the younger age groups. Among
all respondents under age 85, even those whose incomes were at
six times the poverty threshold had significantly higher odds of
reporting functional limitations, compared with the wealthiest
group.
The poverty threshold in 2000, the year the data were collected,
was $8,259 for a person age 65 or older who lived alone and $17,761
for a four-person household. The highest income category used in
the analysis — 700 percent or more of the poverty line — began
at $57,813 for an older adult living alone and $124,327
for a four-person household.
The research was supported by the Retirement Research Foundation
and the NIA. The NIA leads the federal effort supporting and
conducting research on aging and the medical, social and behavioral
issues of older people. For more information on research and
aging, go to www.nia.nih.gov. Publications
on research and on a variety of topics of interest on health
and aging can be viewed and ordered by visiting the NIA Web site,
or can be ordered by calling toll free 1-800-222-2225.
The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.