The Whitehall study of civil servants

Between September 1967 and January 1970, 19,019 men aged 40 to 69 who worked for the civil service in London filled in a questionnaire and had a medical examination. Staff recorded height, weight and blood pressure, ran electrocardiograms and lung function tests, and drew blood for cholesterol and glucose. Each man also gave his civil service employment grade. The study was set up, at the peak of Britain's epidemic of vascular disease, to measure how well risk factors predicted coronary and other vascular deaths.

In December 1978 Michael Marmot, Geoffrey Rose and two colleagues reported on 17,530 of the men after seven and a half years of follow-up. The lower a man's grade, the higher his risk of dying of coronary heart disease. Messengers, in the lowest grade, had 3.6 times the coronary death rate of administrators in the highest.

Men in the lower grades were shorter and heavier for their height, had higher blood pressure and plasma glucose, smoked more and reported less physical activity in their leisure time. Yet when the authors allowed for all of these, and for plasma cholesterol, the link between grade and coronary death stayed strong. They concluded that the higher coronary mortality of working-class men, which also appeared in national statistics, could be only partly explained by the established risk factors.

Rose used the initial Whitehall results to compare high-risk and population strategies for preventing cardiovascular disease. Follow-up went on for 38 years. By then 13,501 of the 18,863 men examined at entry had died, and 4,811 were examined again in 1997. Men in the top 5 percent of a risk score that combined employment grade with smoking, diabetes, blood pressure, cholesterol and body mass index could expect to live 20.2 more years from age 50, against 35.4 years for men in the bottom 5 percent.