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RCT Testing Bystander Effectiveness to Reduce Violence

NCJ Number
American Journal of Preventative Medicine Volume: 52 Issue: 5 Dated: 2017 Pages: 566-78
Date Published
13 pages

This paper uses an intent-to-treat (TT) analysis in its examination of the impacts of a bystander intervention program in Kentucky high schools; it discusses the authors’ methodology and results regarding the program’s effects on school-level frequency of sexual violence as well as sexual harassment, stalking, and dating violence.


The authors report on a study that evaluated the Green Dot bystander intervention, aimed at reducing sexual violence and related forms of interpersonal violence in 26 high schools over five years. The authors performed a cluster randomized controlled trial (RCT) in Kentucky high schools, which were randomly placed in intervention or control (wait list) conditions. For the intervention, Green Dot−trained educators conducted schoolwide presentations and recruited student popular opinion leaders to receive bystander training in intervention schools beginning in Year One. For the study, sexual violence perpetration, and related forms of interpersonal violence victimization and perpetration were measured using anonymous student surveys that were collected at baseline and annually, from 2010 to 2014. Because the school was the unit of analysis, violence measures were aggregated by school and year and school-level counts were provided. A total of 89,707 students completed surveys. The primary, as randomized, analyses conducted in 2014–2016 included linear mixed models and generalized estimating equations to examine the condition−time interaction on violence outcomes. During Years three and four, when Green Dot was fully implemented, the mean number of sexual violent events prevented by the intervention was 120 in Intervention Year Three and 88 in Year Four. The authors observed similar patterns for sexual violence victimization, sexual harassment, stalking, and dating violence perpetration and victimization. The authors conclude that implementation of Green Dot in Kentucky high schools significantly decreased not only sexual violence perpetration but also other forms of interpersonal violence perpetration and victimization. Publisher Abstract Provided

Date Published: January 1, 2017