Sir Austin Bradford Hill: medical statistics and the quantitative approach to prevention of disease.

Sir Austin Bradford Hill (1897-1991), son of a prominent medical physiologist, was destined for the study of medicine when World War I intervened. He chase to enlist as a pilot in the Royal Navy Air Service. Having contracted tuberculosis on his way to the Dardanelles, Hill was 'sent home to die'. In spite of the odds he recovered; but with no chance of working in physically taxing fields such as medicine or science. Advised and encouraged by Major Greenwood, he carved out for himself a career in medical statistics, first at the Medical Research Council and subsequently at the London School of Hygiene and Tropical Medicine, where his inspired teaching helped to shape the development of medical research in the second half of the twentieth century. He is particularly remembered for the way he made medical statistics an essential part of modern epidemiology, a new phase in an epidemiology concerned with chronic as well as with infectious diseases. At the same time, he introduced randomization where therapies-beginning with streptomycin in tuberculosis-could be evaluated in large-scale clinical trials. Perhaps his best known achievement is his design of the smoking and lung cancer trials, carried out with Richard Doll who later extended-and still extends-the trials which so convincingly have linked addiction to tobacco to patients' later problems with cancers and with coronary heart disease.