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 is still continuing. All study participants are registered with the Office of National Statistics (ONS) to obtain mortality data (date of and cause of death) are provided by NHS Digital on behalf of ONS and is sourced from Civil Registration Data. Study participants are also registered with the National Cancer Registration and Analysis Service (NCRAS) to obtain cancer diagnoses.
This information received from NHS Digital and NCRAS (which is patient identifiable data) will be imported to a securely accessed computer by The University of Oxford (Data Controller), and used solely for academic research purposes by the study team in Oxford. Before analysing this complete dataset (including information already provided by the study participants, patient identifiers will be removed. Importantly, whilst the information received is specific to each study participant, no individual person will be identifiable in any publication arising from this work. Furthermore, the British Doctors Study database will not be shared with organisations outside of the University of Oxford and only accredited researchers in Clinical Trial Service Unit & Epidemiological Studies Unit (CTSU), University of Oxford will have access to the data. Anonymous results of the study may be made available to collaborators and relevant bone fide researchers according to the Nuffield Department of Population Health (NDPH), data sharing policy see: https://www.ndph.ox.ac.uk/data-access
Funding for this long term follow-up is from the UK Medical Research Council, Cancer Research UK, and British Heart Foundation.
What to do next?
If participants decide they no longer want their study data to be linked in this way they can withdraw from this follow-up, without affecting their current medical care, by contacting the Study Coordinator, Dr Hongchao Pan at:
Medical Research Council Population Health Research Unit
Clinical Trial Service Unit & Epidemiological Studies Unit
Nuffield Department of Population Health
Richard Doll Building
Old Road Campus
Oxford OX3 7LF
or Tel: +44 (0)1865 743835 (direct) between 9-4pm on weekdays.