The health of older Britons is generally better than that of Americans of similar age, but health insurance–or the lack of it–does not appear to explain the difference, a new study finds.

Moreover, health differences could not be attributed to differences among the two groups in smoking, obesity, consuming too much alcohol or any of the other “usual suspects,” according to authors of the study, published in the May 2006 issue of the Journal of the American Medical Association.

The study of around 8,100 Americans and British aged 55 to 64 was conducted by researchers from University College London, the College of London and the Rand Corp., Santa Clara, Calif.

The principal author, James Banks of University College London, concludes “Americans are much sicker than the English.”

This was despite average per-capita spending on medical care of $5,274 in the U.S., compared to $2,164 in England, the article noted, citing World Health Organization data.

The U.S. population in late middle age was less healthy than British counterparts for diabetes, hypertension, heart disease, myocardial infarction, stroke, lung disease and cancer, Banks and colleagues found.

Within each country, poor health was worst among those at the bottom of the education or income ladder. Behavioral risk factors, including smoking and obesity, explained little of these health differences, according to the article.

Among those aged 55 to 64, diabetes prevalence is twice as high in the U.S., but the researchers could explain only about 20% of this difference by common behavioral risk factors.

Among health threats studied, mean levels of C-reactive protein (an indicator of cardiovascular disease risk) were 20% higher in the U.S. than in England, while mean high-density lipoprotein cholesterol levels (called “good” cholesterol because it helps prevent cholesterol buildup in the arteries) were 14% lower.

For many diseases, even people at the top of the income and education scale for the sampled age group was less healthy in the United States than in Britain, the researchers report.

Differences in socioeconomic groups between the two countries were so great that those in the top education and income level in the U.S. had similar rates of diabetes and heart disease as those in the bottom education and income level in England, the article reports.

Researchers could not attribute health disparities in the two countries to differences in health care insurance coverage.

“Although access to health care is important, differential access can only offer a partial explanation for our findings,” the authors conclude. “Health insurance cannot be the central reason for the better health outcomes in England because the top socioeconomic status tier of the U.S. population have close to universal access but their health outcomes are often worse than those of their English counterparts.”

The study was based on data for 2002 from the U.S. Health and Retirement Survey by the U.S. Census Bureau and the English Longitudinal Study of Aging, along with other data.

To eliminate the possible impact of ethnic differences on study results, only data on non-Hispanic whites in both countries was examined.