A、15% B、17% C、7% D、5% C

AMERICA’s medical system has long seemed a poor bargain. Americans spend far more on health care than the inhabitants of other rich countries, but their life expectancy is below the wealthy world’s average. Annual medical costs, measured by the Organization for Economic Co-operation and Development using purchasing-power parities, which take account of price differences, amount to ＄5,635 per person in America compared with ＄2,231 in Britain. Yet an American’s life expectancy at birth is 77.2 years compared with 78.5 for a Briton.
    Life expectancy, though, is a crude and indirect measure of health. For example, two factors contributing to America’s poor showing have nothing to do with the victim’s health. These are a high rate of road-accident mortality, and the highest homicide rate in the rich world. To overcome this deficiency, a study just published in the Journal of the American Medical Association by Michael Marmot, of University College, London, and his colleagues uses direct measures to compare the health of middle-aged Americans and Britons --and the results still favor the Limeys.
    Strictly, the comparison was between Americans and the English. Scots, with their notoriously high rates of heart disease, were conveniently excluded by the choice of the English Longitudinal Study of Ageing as the source Of the British data, as were the Welsh and the Northern Irish. With this caveat, Dr Marmot’s research revealed that people who are between 55 and 64 years of age are a lot sicker in America than they are in England. Diabetes is twice as common: 12.5% of Americans suffer from it, compared with 6.1% in England. Cancer is nearly twice as prevalent in America, while heart disease is half as high again.
    America’s greater ethnic diversity is not the mason as why middle-aged Americans are so much sicker than their English counterparts, since the research excludes blacks and Latinos (in England, it excludes Asians and blacks, to make the populations comparable). Access to health care is an obvious suspect, because America, unlike other rich countries, does not have universal coverage. Official figures show that 16% of the population is uninsured. However, only 7% of the middle-aged Americans in the survey lacked health insurance, while within the top third by income, access was almost universal. Yet such people were generally sicker than the top third of the English group. Insurance gaps are thus not to blame for Americans’ poorer health.
    Nor are unhealthy lifestyles the main culprit, say the researchers. Smoking rates among this age group are slightly higher in England. Obesity is more common in America, but heavy drinking is more widespread in England. Altogether, these risk factors explain very little of the health disparity between the two countries. For example, they account for less than a fifth of the difference in diabetes.
    The study thus establishes that middle-aged Americans are much sicker than their English counterparts without being able to pinpoint why. One possibility is that ill health in America reflects obesity in the past as well as today. In 1980, 15% of Americans were already obese compared with 7% of Britons. England might, thus, simply be lagging behind America in the medical impact of prolonged obesity.