Estimation of relative risk from vital data: smoking and cancers of the lung and bladder.

Mortality data from cancers of the lung and bladder in England and Wales were analyzed. With the use of detailed information on cigarette consumption, a nonlinear least-squares analysis showed that the differences between males and females in the rates of these cancers could be explained on the basis of differences in smoking habits. Furthermore, estimates of the relative risk due to smoking were obtained. The relative risks of smoking 146,000 cigarettes (equivalent to 20 cigarettes/day for 20 yr) were 4.3 for lung cancer and 2.9 for bladder cancer. These estimates agree with those obtained by other types of epidemiologic studies.