In 1922, Hill went to work for the Industry Fatigue Research Board. He was associated with the medical statistician
Major Greenwood and, to improve his statistical knowledge, Hill attended lectures by
Karl Pearson. When Greenwood accepted a chair at the newly formed
London School of Hygiene and Tropical Medicine, Hill moved with him, becoming Reader in Epidemiology and Vital Statistics in 1933 and Professor of Medical Statistics in 1947. In 1947, he was appointed Honorary Director of the Medical Research Council's Statistical Research Unit. is generally accepted as the first modern randomised clinical trial. The use of randomisation in agricultural experiments had been pioneered by
Ronald Aylmer Fisher. The second study was rather a series of studies with
Richard Doll on smoking and lung cancer. The first paper, published in 1950, was a
case-control study comparing lung cancer patients with matched controls. Doll and Hill also started a
long-term prospective study of smoking and health. This was an investigation of the smoking habits and health of 40,701 British doctors for several years (
British doctors study). Fisher was in profound disagreement with the conclusions and procedures of the smoking/cancer work and from 1957 he criticised the work in the press and in academic publications. In 1965, built upon the work of
Hume and
Popper, Hill suggested several aspects of
causality in medicine and biology, which have remained in use by epidemiologists to date. On Hill's death in 1991,
Peter Armitage wrote, "to anyone involved in medical statistics,
epidemiology or public health, Bradford Hill was quite simply the world's leading medical statistician." ==Honours==