Development of smoking by birth cohort in the adult population in eastern Finland 1972-97

Objective-To analyse the dynamics of smoking prevalence, initiation, and ce ssation in relation to sex, age, birth cohort, study year, and educational level. Design-Six independent cross-sectional population surveys repeated every fi ve years between 1972 and 1997. Setting-The provinces of North Karelia and Kuopio in eastern Finland. Subje cts-Independent random samples of 18 088 men and 19 200 women aged 25-64 ye ars. Those comprising the oldest birth cohort were born in 1913-17 and thos e in the youngest were born in 1968-72. Results-Among men the prevalence of smoking decreased over time, but the co hort effect observed in smoking initiation was obscured by the changes in s moking cessation. Differences between the educational categories were small . Among women the prevalence of smoking increased during the study period. This was mainly caused by the less highly educated, in whom smoking initiat ion clearly increased in successive birth cohorts, but a more moderate coho rt effect was also present among the more highly educated women. Conclusions-In men decreased initiation and increased cessation contributed to the downward trend in smoking prevalence, whereas among women, changes in smoking were mostly caused by augmented initiation in successive birth c ohorts. During the study period educational inequalities in smoking widened , as the less highly educated came increasingly to form the smoking populat ion.