Effectiveness of Intervention on Reducing the Prevalence of Smoking Among Adolescents

In this multicenter cluster randomized controlled trial stratified by school baseline prevalence of smoking will be randomly allocated to the control or intervention group. Control schools will receive normal smoking education and intrvention schools will receive a four year class-based curriculum intervention (22 Classroom lessons), reinforcement of smoke-free school policy, smoking cessation in parents, pupils, and teachers and information and annual meeting with parents. Study participants will be children aged 12 to 15 years old ; they will be followed to 2 years after high school. External evaluator and analyst will be blinded to school allocation. The aim of this study is to analyze the effectiveness of a complex intervention to reduce the prevalence of smoking at 3º ESO (14-15 yrs-old) and 2 years after high school (17-18 yrs-old) .