Mortality in relation to smoking: 40 years' observations on male British doctors

To assess the hazards associated with long term use of tobacco.Prospective study of mortality in relation to smoking habits assessed in 1951 and again from time to time thereafter, with causes sought of deaths over 40 years (to 1991). Continuation of a study that was last reported after 20 years' follow up (1951-71).34,439 British male doctors who replied to a postal questionnaire in 1951, of whom 10,000 had died during the first 20 years and...