British Doctors Study
The British Doctors Study, which began in 1951, was the world’s first large prospective study of the effects of smoking to establish a convincing linkage between tobacco smoking and cause-specific mortality, and demonstrated prospectively the risk of death from lung cancer (1954) and myocardial infarction and chronic obstructive pulmonary disease (1956).
Its results, then and subsequently (particularly the 10-year, 20-year, 40-year and 50-year results), have substantially influenced national and personal decisions about quitting, as they assessed the lifelong effects of smoking seriously and then of stopping seriously.
In October 1951, Sir Richard Doll and Sir Austin Bradford Hill sent a questionnaire on smoking habits to all registered British doctors. Of the 59600 questionnaires mailed, 41024 replies were received and 40701 (34494 males and 6207 females) were sufficiently complete to be included in the follow-up. Further questionnaires about changes in smoking habits were sent in 1957, 1966, 1971, 1978, 1991, 1998 and 2001. Because of the limited sample size and limited tobacco consumption females were excluded from most reports, and the study has focused on the males.
The 1978 questionnaire sought information from all male doctors born in the 20th century about a wider range of characteristics (including alcohol consumption and self-reported body mass index) and invited them to participate a randomised trial of prophylactic daily aspirin to prevent death from stroke, myocardial infarction, or other vascular conditions. This trial has engendered others, some much larger, and has contributed to statistically stable meta-analyses of all trials.
Follow-up of the incidence of cancer and of cause-specific mortality among the male doctors was still continuing in 2015, by which time even the youngest participants were 85 years old.The current and planned analyses are
- Mortality in relation to smoking: 63 years’ observations on male British doctors
- Mortality in relation to alcohol consumption: 36 years' observations on male British doctors.
Funding for this project is from the UK Medical Research Council, Cancer Research UK, and British Heart Foundation