Predictors of susceptibility to smoking and ever smoking: a longitudinal study in a triethnic sample of adolescents.

This report describes a longitudinal study of the natural course of smoking initiation in a school-based, ethnically diverse (42% White, 37% African American, 20% Hispanic) sample of adolescents in grades 5, 8, and 12 who were followed prospectively for 1 year. A cohort of 659 students was identified who were never smokers at baseline and who completed questionnaires both at baseline and at 1-year follow-up. From this cohort, predictor variables were used to identify ethnic-specific risk factors for (a) "susceptibility to smoking" among the 509 students who were nonsusceptible, never smokers at baseline and (b) "ever smoking" among all 659 students who were never smokers at baseline (both susceptible and nonsusceptible). Logistic regression analyses revealed that parental and household influences (parental education, marital status, household smoking) were important predictors of ever smoking, but not of susceptibility to smoking, for African Americans. Hispanic adolescents were significantly influenced by environmental influences, namely smoking by other household members (ever smoking) and by peers (susceptibility and ever smoking), although peer pro-tobacco influences (friends who smoke or friends' approval of smoking) were important predictors of susceptibility to smoking or ever smoking for all three ethnic groups. Exposure to tobacco-related advertising was a risk factor for White (susceptibility and ever smoking) and African American (susceptibility only) adolescents but not for Hispanic adolescents. Inclusion of the susceptibility to smoking variable in the model predicting ever smoking substantially reduced the importance of other predictors in the model, suggesting that susceptibility to smoking was not an independent risk factor for ever smoking but rather a potential mediating variable. The results of this study offer important insights for designing ethnic-specific strategies for preventing smoking during adolescence.