Predictors of transition in different stages of smoking: a longitudinal study.
BACKGROUND
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 10(th) grade students in Tabriz, 1785 students were randomly selected and assessed twice, with a 12-month interval, with respect to the changes of stage. The predictor variables were measured when the students were in the 10(th) grade. Logistic regression and principal component analysis were used to analysis data at grade 11.


RESULTS
Of 1785 students, 14.3% (CI 95%: 12.3-16.4) and 2.8% (CI 95%: 2.0-4.0) of the never smokers became experimenters and regular smokers, respectively and 16.5% (CI 95%: 12.4-21.7) of the experimenters became regular smokers. Among never smokers, participating in smoker groups (OR=1.24), having smoker friends (OR=1.85) and a positive attitude towards smoking (OR=1.22) predicted experimentation; and participating in smokers groups (OR=1.35) and a lower socioeconomic class (OR=0.36) predicted regular smoking. Among experimenters, students having general high risk behaviors (OR=2.56) and participating in smoker groups (OR=2.58) were distinguished as those who progressed to regular smoking in follow-up.


CONCLUSIONS
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.
PhD Student, Department of Epidemiology and Biostatistics, School of Public Health and Public Health Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Asghar
A
Mohammadpoorasl
Associate Professor of Psychiatry, Tabriz University of Medical Sciences, Tabriz, Iran.
Ali
A
Fakhari
Lecturer, National Public Health Management Center, Tehran, Iran.
Fatemeh
F
Rostami
MSc Student, Department of Epidemiology and Biostatistics, School of Public Health and Public Health Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Mansour
M
Shamsipour
MSc Student, Department of Epidemiology and Biostatistics, School of Public Health and Public Health Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Hamideh
H
Rashidian
Professor of Psychiatry, Tabriz University of Medical Sciences, Tabriz, Iran.
Mohammad Ali
MA
Goreishizadeh
Epidemiology; Longitudinal studies; Peer group; Prevalence; Risk factors; Risk-Taking; Smoking; Students