the association of the transitions in smoking stages with prevalence of cigarette smoking in the classes and schools: a longitudinal study

background: adolescent tobacco use remains a major public health priority to reduce the prevalence of tobacco use in community. the aim of this study was determining the association of the transitions in smoking stages with prevalence of cigarette smoking in the classes and schools in adolescents of tabriz city (northwest of iran). methods: fifty-six high schools were randomly selected, and 4903 students completed a self-administered questionnaire on cigarette smoking twice with a 12-months interval in 2010 and 2011. results: transition from experimenter to regular smoker stage was associated with the prevalence of cigarette smoking in the school. conclusions: the results have shown the association of student's smoking uptake with the prevalence of cigarette smoking in the school. this highlights the importance of enforcing smoke free policies in schools.