Boulter 1997.

Methods	Cluster‐RCT. 8 fraternities and halls of residence assigned to treatment or wait list control by "random draw"
Participants	55 fraternity members and residents of male residential halls within a large rural university, USA. Males only. Aged 19‐25 years, mean 20.77 years
Interventions	Intervention: acquaintance rape prevention programme consisting of discussion and video on acquaintance rape and the law. Delivered by female doctoral student of counselling psychology and sexual educators from campus peer education programme. The intervention was delivered as a single 1‐hour session. 23 students Control: 'wait list control' (i.e. received the intervention after completion of data collection). 32 students
Outcomes	Knowledge/acceptance of rape myths, as measured by a modified version of the Rape Myth Acceptance Scale and a modified version of the Acceptance of Sexually Coercive Strategies Scale
Follow‐up	6 and 10 weeks post‐test
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Assignment to groups occurred by "a random drawing"
Allocation concealment (selection bias)	Unclear risk	Not stated
Incomplete outcome data (attrition bias) All outcomes	High risk	High attrition rates (due to participants not completing all 3 phases of study): intervention 70% (53/76); control 68% (67/99)
Selective reporting (reporting bias)	Low risk	All outcomes reported in full (number of participants, means, SDs)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding not possible. Facilitators of intervention programme had extensive experience in presentations on topic of sexuality, but no mention made of how uniformity of delivery was assessed
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not stated