Objective: To conduct a systematic review of rigorously evaluated school-based interventions to decrease bullying.
Data sources: MEDLINE, PsycINFO, EMBASE, Educational Resources Information Center, Cochrane Collaboration, the Physical Education Index, and Sociology: A SAGE Full-Text Collection were searched for the terms bullying and bully.
Study selection: We found 2090 article citations and reviewed the references of relevant articles. Two reviewers critically evaluated 56 articles and found 26 studies that met the inclusion criteria.
Interventions: The types of interventions could be categorized as curriculum (10 studies), multidisciplinary or "whole-school" interventions (10 studies), social skills groups (4 studies), mentoring (1 study), and social worker support (1 study).
Main outcome measures: Data were extracted regarding direct outcome measures of bullying (bullying, victimization, aggressive behavior, and school responses to violence) and outcomes indirectly related to bullying (school achievement, perceived school safety, self-esteem, and knowledge or attitudes toward bullying).
Results: Only 4 of the 10 curriculum studies showed decreased bullying, but 3 of those 4 also showed no improvement in some populations. Of the 10 studies evaluating the whole-school approach, 7 revealed decreased bullying, with younger children having fewer positive effects. Three of the social skills training studies showed no clear bullying reduction. The mentoring study found decreased bullying for mentored children. The study of increased school social workers found decreased bullying, truancy, theft, and drug use.
Conclusions: Many school-based interventions directly reduce bullying, with better results for interventions that involve multiple disciplines. Curricular changes less often affect bullying behaviors. Outcomes indirectly related to bullying are not consistently improved by these interventions.