The longitudinal age and birth cohort trends of smoking in Sweden: a 24-year follow-up study

The aim of this study is to analyse longitudinally, the annual effects of age group and birth cohort on smoking in the Swedish population during a 24-year period and to analyse the smoking trends for different levels of education. A random sample of adult, non-institutionalized persons aged 16–71 years was interviewed every 8 years by professional interviewers. In addition to three time-related variables—year of interview, age at the time of the interview, and year of birth—we included the following explanatory variables in the analyses: sex, educational level, and urbanization. We found significant decreases in smoking prevalence in all studied subgroups. The adjusted odds ratios for age were 0.89 (95 % CI 0.88–0.90) and 0.92 (95 % CI 0.91–0.93) for men and women, respectively. The decreases in smoking over time were significant in all levels of education, except for in women with low educational level. In Sweden, the prevalence of smoking has decreased in most age groups and cohorts, and in persons in most levels of education, albeit less so in women with low educational level.