Do adolescents' own intentions regarding healthy behaviours affect outcome? A two-year prospective study.

Adolescents' own intentions regarding health behaviours, in addition to their context, are believed to be important for the health habits they chose. This was studied prospectively over a 2-y period. A total of 552 students, 391 aged 13 y and 161 aged 15 y, reported their health and problem behaviours, socioeconomic background and intentions regarding health behaviours through questionnaires in 1991 and in 1993. Outcome dealt with three domains: health habits; acquisition of adult lifestyles; and problem behaviours. The material was analysed for correlations. Significant results were entered into multiple regression stepwise procedures. As expected, already having initiated adult lifestyles or problem behaviours were the most important factors associated with such behaviours 2 y later. Further analyses were then limited to those students who had not started such lifestyles, in order to determine what factors kept them from doing so in a 2-y span. Key predictors for healthy behaviours were adolescents' own decisions not to engage in adult lifestyles or risky behaviours, family processes consistent with support and school satisfaction. Association with peer groups where smoking and drinking were commonplace predicted less optimal behaviours. Gender or socioeconomic factors were not predictive. The results support a comprehensive approach to health promotion during adolescence.