MORTALITY IN RELATION TO TAR YIELD OF CIGARETTES - A PROSPECTIVE-STUDY OF 4 COHORTS

Objective--To investigate relation between tar yield of manufactured c igarettes and mortality from smoking related diseases. Design--Prospec tive epidemiological study of four cohorts of men studied between 1967 and 1982. Setting--Combined data from British United Provident Associ ation (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 wer e included in the studies, 2742 deaths occurred among 12 400 smokers. Average follow up was 13 years. Main outcome measures--Relative mortal ity from smoking related diseases according to tar yields of cigarette s smoked. Results--Age adjusted mortality from smoking related disease s in smokers of filter cigarettes was 9% lower (95% confidence interva l 1% to 17%) than in smokers of plain cigarettes (P=0.017). Mortality from smoking related diseases consistently decreased with decreasing t ar 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 disease, 0.7 8 (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 possib ly other smoking related diseases would have been avoided by lowering tar yield from 30 mg per cigarette to 15 mg. Reducing cigarette tar yi elds in Britain has had a modest effect in reducing smoking related mo rtality.