A Multilevel Latent Class Analysis of Smoking Stages in Adolescents and its Predictors

Adolescent smoking status were powerful predictors for adult smoking where the most people who started smoking at lower ages continueed to smoke later. The smoking process is complicated and is not limited to smokers and non-smokers, but includes patterns and different stages that need to be identified and evaluated . The main objectives of the current study is to identify stages of smoking in adolescents and to assess factors influencing the patterns of smoking in this population. Using the multistage random sampling, 56 high schools with a total of 205 classrooms were randomly selected. The total number of 4907 high school students in Tabriz, Iran participated in the current study and completed a self-administered questionnaire. Multilevel latent class analysis was used in smoking stage determination. Three stages of smoking were identified non-smokers, moderate, and heavy smokers with prevalence 71.3%, 22.4%, and 6.3%, respectively. In gender specific analysis, such figures were 82.6%, 14.5%, and 2.7% for girls and 77.3%, 15.6%, and 7% for boys, respectively. Age, the grade point average, living with parents, having smoking friends and family, risk taking behaviors, self-injury, attitude and positive thinking about smoking were significantly associated with smoking stages in students. The social-economic status did not have significant association with smoking stage. Using multilevel classification technique that consider the hierarchal construct of data, a more reliable stages of smoking was measured in male and female adolescents.