Preventing the onset of cigarette smoking in Norwegian adolescents: the Oslo youth study.

As part of a 2-year multiple risk factor intervention study, a school-based, multicomponent smoking prevention program for 10- to 15-year-old students in Oslo, Norway, resulted in a significant reduction in the onset of smoking relative to a reference group. Based on reported smoking behavior, the intervention group (N = 278) experienced a smoking onset rate of 16.5% and the reference group (N = 208) a rate of 26.9%. Intervention students had a significantly larger increase in scores on a smoking knowledge index; they also reported a significantly larger increase in frequent exercise and a significantly smaller increase in consumption of alcoholic beverages. A stepwise discriminant analysis showed that the smoking prevention program was an important discriminator of smoking onset. In both reference and intervention groups, students who reported smoking at the follow-up survey had already displayed risk-taking tendencies at the time of the baseline survey 2 years earlier, whether or not they smoked at baseline. Follow-up smokers had more smoking friends and siblings at baseline and evidenced greater acceptability of smoking; they ate sweet, fatty, and salty snack foods more often, exercised less often, and drank more beer and hard liquor than students who were nonsmokers at the follow-up survey.