Asghar Mohammadpoorasl - Msc of Epidemiology, Tabriz University of Medical Science
Ali Fakhari - Associate Professor of Psychiatry Tabriz University of Medical Science
Fatemeh Rostami - MSc. of pediatric Nursing, Lecturer, National Public Health Management Center
Mansour Shamsipour - MSc. Student, Department of Epidemiology and Biostatistics, School of Public Health and Institute of Public Health Research, Tehran University of Medical Science
Hamideh Rashidian - MSc. Student, Department of Epidemiology and Biostatistics, School of Public Health and Institute of Public Health Research, Tehran University of Medical Science
Mohammad Ali Goreishizadeh - Professor of Psychiatry Tabriz University of Medical Science

AbstractBackground: We investigated longitudinally the prevalence of smoking according to three stages of smoking (never smoking, experimenting the smoking, and regular smoking), the rates of transition from one stage to another one, and determinant predictors of transition through these stages of smoking.Methods: Of all ۱۰th grade students in Tabriz, ۱۷۸۵ students were randomly selected and assessed twice, with a ۱۲-month interval, with respect to the changes of stage. The predictor variables were measured when the students were in the ۱۰th grade. Logistic regression and principal component analysis were used to analysis data at grade ۱۱.Findings: Of ۱۷۸۵ students, ۱۴.۳% (CI ۹۵%: ۱۲.۳-۱۶.۴) and ۲.۸% (CI ۹۵%: ۲.۰-۴.۰) of the never smokers became experimenters and regular smokers, respectively and ۱۶.۵% (CI ۹۵%: ۱۲.۴-۲۱.۷) of the experimenters became regular smokers. Among never smokers, participating in smoker groups (OR = ۱.۲۴), having smoker friends (OR = ۱.۸۵) and a positive attitude towards smoking (OR = ۱.۲۲) predicted experimentation; and participating in smokers groups (OR = ۱.۳۵) and a lower socioeconomic class (OR = ۰.۳۶) predicted regular smoking. Among experimenters, students having general high risk behaviors (OR = ۲.۵۶) and participating in smoker groups (OR = ۲.۵۸) were distinguished as those who progressed to regular smoking in follow-up.Conclusion:Programs aimed at smoking prevention and intervention should incorporate plans which focus on predictors of transition through smoking stages, and targeting participation in smoker groups.Keyword: Smoking, Students, Risk-Taking, Longitudinal Studies, Peer Group, Epidemiology, Prevalence, Risk factors