journal · Public research summary
Mortality in relation to smoking: 50 years’ observations on male British doctors
Stopping at approximately 60, 50, 40 or 30 was associated with about 3, 6, 9 or 10 years relative to continuing.
Educational only. Associations do not establish individual risk or diagnosis. Read the original sources and limitations. Editorial review: 2026-10-06.
Citation
Doll R et al. · BMJ · 2004 · DOI: 10.1136/bmj.38142.554479.ae
Study design
50-year prospective cohort
Population
34,439 male British doctors followed from 1951 to 2001.
Measured outcome
Mortality and life expectancy
Finding
Stopping at approximately 60, 50, 40 or 30 was associated with about 3, 6, 9 or 10 years relative to continuing.
Limitations
Historical male occupational cohort; not automatically representative of women or other populations. Do not add these years to the Jha estimates—they address the same exposure.
Habit topics
Stay smoke-free; get support to quit
Interpretation
Research comparisons are not personal lifespan predictions. Years from different studies, habits, populations and outcomes cannot be added. Supporting studies do not validate the numeric estimate of another study.