|Study Finds Middle-Aged Americans Not as Healthy as English
White middle-aged Americans are not as healthy as their English counterparts,
and in both countries lower income and education levels are associated with poorer
health, according to a new comparison of key American and English health surveys.
The healthiest Americans in the study — those in the highest income and
education levels — had rates of diabetes and heart disease similar to the
least healthy in England — those in the lowest income and education levels
there. The research was supported by the National Institute on Aging (NIA), part
of the National Institutes of Health in the U.S. Department of Health and Human
Services, and British government agencies.
James Smith, Ph.D., of the RAND Corporation, Zoe Oldfield, M.Sc., of the University
of London, and Sir Michael Marmot, M.D., and James Banks, Ph.D., both of University
College, London, reported the comparison in the May 3, 2006, issue of the Journal
of the American Medical Association.
“This comparison raises some important questions about the relationship among
health, education and income in both countries,” says Richard J. Hodes, M.D.,
director of NIA. “As many nations try to address the challenges of population
aging, it will be critical to know why these differences in health status appear.”
Smith and colleagues chose comparable representative samples of people ages
55 to 64 from two large, national health surveys — 4,386 from the U.S.
Health and Retirement Study and 3,681 from the English Longitudinal Study of
Aging. Each sample was divided into three socioeconomic groups based on education
and income. Both samples were limited to non-Hispanic white populations, allowing
the researchers to control for special issues in different racial/ethnic communities
in both countries.
“This study challenges the theory that the greater heterogeneity of the U.S.
population is the major reason the United States is behind other industrialized
nations in some important health measures,” says Richard M. Suzman, director
of NIA’s Behavioral and Social Research Program. “By focusing on the comparable
white populations, this study still finds the U.S. lagging.”
Comparing self-reports of chronic diseases such as diabetes and heart disease
between the two countries, the researchers found that Americans reported significantly
higher levels of disease than the English. For example, the prevalence of diabetes
in the age group was twice as high in Americans as in the English. Also, the
lowest income and education group in each country reported the most cases of
diabetes, hypertension, heart disease, heart attacks, strokes and chronic lung
disease, while the highest income and education groups reported the least. The
only disease for which this inverse relationship was not true was cancer. Smith
and colleagues also found that differences between the two countries in smoking,
obesity and alcohol use explained little of the difference.
Because self-reporting of diseases may have differed between the two countries,
the researchers expanded their study groups to include samples of similar age
groups from the National Health and Nutrition Examination Survey in the United
States and the Health Survey for England. Both of these surveys include clinical
measurements of risk for heart disease and stroke, including C-reactive protein,
fibrinogen and HDL (high-density lipoprotein) cholesterol tests and clinical
examination. These measurements confirmed the differences in diabetes and hypertension
prevalence between the two countries. The differences in health status by income
and education levels also persisted.
Smith, Marmot and colleagues point out that the differences exist despite greater
American health care expenditures, similar patterns in life expectancy between
the two countries, and the fact that smoking behavior in the two countries is
similar. The authors suggest some possible areas for further consideration and
study. For example, other research suggests that different experiences with disease
in childhood could account for some observed differences in adult disease. Also,
the researchers noted, social programs in Great Britain might help protect those
who are sick from loss of income and poverty, and the lack of such programs in
the United States may explain the greater association between health and wealth
for Americans found in studies by Smith and others. Further, extending the study
to other countries with different health systems, such as Canada and the rest
of Europe, and looking at minorities would allow experts to compare the effects
of publicly funded health care in each country.
The National Institute on Aging 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 http://www.nia.nih.gov.
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.