Effect of a Behavioral Intervention on Perpetrating and Experiencing Forced Sex Among South African Adolescents: A Secondary Analysis of a Cluster Randomized Trial

IMPORTANCE: Scant research has investigated interventions to reduce forced sexual intercourse among adolescents. The need for such interventions is especially great in South Africa, which has some of the highest rates of sexual assault in the world. OBJECTIVES: To determine whether an HIV/sexually transmitted disease risk-reduction intervention that reduced sexual risk behavior and sexually transmitted disease prevalence also reduced the perpetration and experience of forced sex among South African adolescents. DESIGN, SETTING, AND PARTICIPANTS: A cluster randomized clinical trial, at schools located in a township and a semirural area, Eastern Cape Province, South Africa. Matched pairs of schools were randomly selected (9 of 17); of 1118 students in sixth grade at these 18 schools who had parent or guardian consent, 1057 (94%) were enrolled, and those not reporting forced sex perpetration before the intervention were included in the analyses (n = 1052). Post hoc secondary analysis of a cluster randomized clinical trial was performed, with baseline and 3-, 6-, 12-, 42-, and 54-month postintervention assessments between October 4, 2004, and June 30, 2010. Generalized estimating equation Poisson regression analyses adjusting for gender and clustering within schools were conducted between August 23, 2017, and April 30, 2018. Recruiters and data collectors, but not intervention facilitators, were blind to the participants’ intervention assignment. INTERVENTIONS: Theory-based, culturally adapted, 6-session HIV/sexually transmitted disease risk-reduction intervention (Let Us Protect Our Future intervention) and attention-matched, chronic disease prevention control intervention implemented by specially trained man and woman cofacilitators from the community. MAIN OUTCOMES AND MEASURES: Study outcomes for this secondary analysis (planned after the data were collected) are self-reports of perpetrating and experiencing forced vaginal intercourse. RESULTS: Participants included 1052 adolescents (557 girls [53%]; mean [SD] age, 12.4 [1.2] years) reporting not perpetrating forced sex at baseline. Fewer intervention than control participants reported forced sex perpetration postintervention compared with the control group at 3 months (9 of 561 [2%] vs 20 of 491 [4%]; risk ratio [RR], 0.978; 95% CI, 0.959-0.997), 6 months (17 of 561 [3%] vs 35 of 491 [7%]; RR, 0.964; 95% CI, 0.941-0.988), 12 months (21 of 561 [4%] vs 42 of 491 [9%]; RR, 0.959; 95% CI, 0.934-0.985), 42 months (41 of 561 [7%] vs 56 of 491 [11%]; RR, 0.967; 95% CI, 0.937-0.998), and 54 months (52 of 561 [9%] vs 68 of 491 [14%]; RR, 0.964; 95% CI, 0.932-0.997). CONCLUSIONS AND RELEVANCE: In settings with high rates of sexual assault, the use of theory-based culturally adapted interventions with early adolescents may reduce rates of perpetrating and experiencing forced sex. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00559403