Long-term effects of implementation intentions on prevention of smoking uptake among adolescents: a cluster randomized controlled trial.

Objective: To test the efficacy of implementation intentions in reducing smoking uptake in a sample of adolescents.

Design: Classes of adolescents (aged 11-12 years) were randomly allocated to one of four conditions: implementation intention, self-efficacy, two control conditions. An implementation intention or a self-efficacy manipulation (both formed in relation to how to refuse offers of cigarettes) was completed by intervention condition participants at 0, 4, 8, 12, 16, 20, and 24 months.

Direct, mediated and moderated impacts of personality variables on smoking initiation in adolescents.

Role of 'Big Five' personality traits as predictors of smoking and moderators of the intention-smoking relationship was tested. Five hundred and fifty-three adolescents (aged 11-12) completed measures of self-reported past smoking, gender, intentions to smoke, perceived behavioural control, family smoking, friends smoking at times 1 and 2 (6 months apart). At time 3, 2 years later, the same adolescents completed measures of the Big Five and self-reported smoking (a subset of 300 also provided an objective smoking measure).