Abstract

Sir Richard Doll, who died in July aged 92, was an epidemiologist who demonstrated one of the most important causality relationships of the past century: the association between smoking and lung cancer. In collaboration with Sir Austin Bradford Hill, Doll conducted first a case control study and then a prospective cohort study of British doctors, comparing rates of lung cancer amongst smokers and nonsmokers. Although only a small number of deaths occurred in the first few years of the cohort study, Doll demonstrated a clear and significant increase in mortality from lung cancer as smoking increased and a smaller but significant increase in coronary thrombosis. In the 1950s, when 80 per cent of the British population smoked, the implications of these findings were very important.