Antibullying Interventions in Schools: Assessing the Evidence Base

Objective: This systematic review used established rating criteria to describe the level of evidence for interventions aimed at preventing or reducing bullying perpetration and victimization in schools, synthesized the evidence for students from racially and ethnically diverse backgrounds, and reviewed the literature for available information to conduct an economic analysis of the interventions. Methods: Major databases, gray literature, and evidence-base registries were searched to identify studies published from 2008 through 2022. The authors rated antibullying intervention models as having high, moderate, or low evidence depending on the number and rigor of studies with positive findings. Results: Overall, 80 articles reporting on 71 original research studies describing a total of 48 antibullying interventions met the inclusion criteria for this review. Two schoolwide interventions received a high-evidence rating: the KiVa (Kiusaamista Vastaan) Antibullying Program and the Friendly Schools program. Multilevel interventions with components at the levels of school, classroom, and individual student most consistently showed strong evidence for reducing bullying behavior in elementary and middle school grades. Four interventions yielded positive effects in reducing bullying and victimization among diverse samples of students. Conclusions: Antibullying interventions can reduce bullying in schools. Some interventions show effectiveness with students from racially and ethnically diverse backgrounds. The gains relative to per-student costs were in the range that is considered cost-effective. Most implementation costs are spent on staff training and support. Research on successful implementation of whole-school interventions and additional synthesis of evidence pertaining to program structures would further advance the antibullying evidence base.