Effects of a skills-based prevention program on bullying and bully victimization among elementary school children.

We report results from a group-randomized trial of a prevention program aimed at preventing bullying and other aggressive behaviors. Fourth grade classrooms at 28 public elementary schools were assigned to receive selected modules of the Youth Matters prevention curriculum or to a no-treatment control condition. Cross-classified multilevel models were fitted to four waves of data collected over 2 years to test the effect of the intervention on self-reported bullying and bully victimization.