Mortality in relation to tar yield of cigarettes: a prospective study of four cohorts.

OBJECTIVE

To investigate relation between tar yield of manufactured cigarettes and mortality from smoking related diseases.

DESIGN

Prospective epidemiological study of four cohorts of men studied between 1967 and 1982.

SETTING

Combined data from British United Provident Association (BUPA) study (London), Whitehall study (London), Paisley-Renfrew study (Scotland), and United Kingdom heart disease prevention project (England and Wales).

SUBJECTS

Of the 56,255 men aged over 35 who were included in the studies, 2742 deaths occurred among 12,400 smokers. Average follow up was 13 years.

MAIN OUTCOME MEASURES

Relative mortality from smoking related diseases according to tar yields of cigarettes smoked.

RESULTS

Age adjusted mortality from smoking related diseases in smokers of filter cigarettes was 9% lower (95% confidence interval 1% to 17%) than in smokers related diseases consistently decreased with decreasing tar yield. Relative mortality in cigarette smokers for a 15 mg decrease in tar yield per cigarette was 0.75 (0.52 to 1.09) for lung cancer, 0.77 (0.61 to 0.97) for coronary heart disease, 0.86 (0.50 to 1.50) for stroke, 0.78 (0.40 to 1.48) for chronic obstructive lung diseases, 0.78 (0.65 to 0.93) for these smoking related diseases combined, and 0.77 (0.65 to 0.90) for all smoking related diseases.

CONCLUSION

About a quarter of deaths from lung cancer, coronary heart disease, and possibly other smoking related diseases would have been avoided by lowering tar yield from 30 mg per cigarette to 15 mg. Reducing cigarette tar yields in Britain has had a modest effect in reducing smoking related mortality.