The effects of different saturation levels of the Shifting Boundaries intervention on preventing adolescent relationship abuse and sexual harassment

Objectives Prior research with the Shifting Boundaries (SB) prevention program suggests that it can prevent adolescent relationship abuse and sexual harassment. We assessed the relative impact of a combined set of SB classroom (SBC) and SB building (school-wide; SBS) interventions on adolescent relationship abuse and sexual harassment outcomes when the program is delivered to all three grades in a middle school (full saturation) compared to when only two or one of the three grades receive it. Methods We randomly assigned 23 middle schools (1,764 students) in New York City to varying saturation levels of SB: 6th grade only, 6th and 7th grade, or 6th, 7th, and 8th grade. Results Providing SB to only one grade level does just as well at preventing peer violence and adolescent relationship abuse as treating multiple grades. However, there was evidence that additional saturation led to sexual harassment reductions. Schools that delivered SB to 6th and 7th graders (compared to just 6th graders) reduced sexual harassment victimization 6 months post-treatment. Conclusions The results largely support a minimalist approach, in that SB may be effective in preventing peer violence and adolescent relationship abuse outcomes by delivery to one grade level. However, there is a need for more research to continue exploring the potential benefits of a saturated delivery of SB across all grades, building on our finding that 6th and 7th grade implementation of SB was more effective at reducing sexual harassment than 6th grade only implementation.