摘要:Objectives. We examined socioeconomic inequalities in initiation and cessation rates of smoking and the resultant inequality in smoking prevalence among 3 consecutive Italian birth cohorts. Methods. We used data from the 1999–2000 Italian National Health Interview Survey, which included 28958 men and 29769 women who were born between 1940 and 1969. The association between smoking variables and level of education was assessed with logistic regression and life table analyses. Results. Inequalities in the lifetime prevalence of smoking increased across the 3 birth cohorts in Italy. At age 40, lower-educated persons in the youngest cohort reported on average 1 to 5 years of additional exposure to regular smoking compared with higher-educated persons. Inequalities in smoking prevalence increased among both men and women because of widening inequalities in initiation rates. Among women, growing inequalities in cessation rates also played a role. Conclusions. The relative contribution of initiation and cessation to socioeconomic inequalities in smoking rates varied by both gender and birth cohort. For the youngest birth cohort, policies that address inequalities in smoking should focus on both initiation and cessation. The association between smoking and low socioeconomic status (SES) has become increasingly stronger in almost all industrialized countries. 1 – 4 This is associated with a shift in the social distribution of smoking over time: higher-SES groups take up the habit before lower-SES groups, but ultimately, this pattern reverses. The transition has been completed in the United States and in several northern European countries, but it is still under way in southern Europe. 1 , 5 Despite this evidence, antitobacco measures in industrialized countries have so far failed to address the widening social inequality in smoking over time, because they have mainly focused on decreasing the overall prevalence of smoking. In a recent review, Platt et al. suggested that a mix of interventions—such as increased taxation, availability of nicotine-replacement therapy, and measures that address the underlying economic and psychosocial determinants of smoking initiation and cessation—may reduce inequality in smoking prevalence. 6 Amos suggested that the effectiveness of antitobacco interventions would be improved if gender differences and stage of the smoking epidemic (i.e., phase of diffusion of smoking within a population) were taken into account. 7 However, it is unknown whether inequalities can be reduced by measures that affect initiation of smoking among adolescents or by measures that affect cessation among adults. We wanted to disentangle the dynamics of inequalities in smoking with data from Italy, a country in which the social distribution of smoking has been rapidly changing. 3 Our goal was to (1) describe socioeconomic inequalities in initiation and cessation rates of smoking and the resultant inequality in smoking prevalence among 3 consecutive Italian birth cohorts, and (2) identify changes among these birth cohorts. More specifically, our first objective was to describe the educational differences (how large the differences were and whether they varied by age) in the 3 indicators associated with tobacco use—probability of taking up the habit, probability of quitting, and prevalence of smoking—for each birth cohort and for both genders. A second specific objective was to estimate whether differences in either initiation or cessation contributed to the inequalities in lifetime prevalence of smoking and whether their relative contribution varied with gender and birth cohort.