Enrollment and Randomization

The Sexual Assault Resistance Education (SARE) Trial was approved by the ethics boards at the Universities of Windsor, Guelph, and Calgary. The full study protocol and the baseline characteristics and sexual assault histories have been published previously4,22; the study protocol is also available with the full text of this article at NEJM.org. The first author assumes responsibility for the fidelity of the report to the protocol and the accuracy and completeness of the data.

In brief, this open-label, randomized, controlled trial enrolled first-year female students, 17 to 24 years of age, at one large university in western Canada and two midsized universities in central Canada, from September 2011 to February 2013. To be eligible for the trial, students had to be able to attend one of four scheduled sets of intervention sessions during the semester in which they enrolled in the study. A total of 69.4% of the participants were recruited through e-mail messages and telephone calls to first-year female students who were registered in the research participant pools of psychology departments; approximately 70% of students on campus register for psychology courses and are thereby included in these pools. Other participants were recruited through posters or flyers around campus, e-mail messages forwarded by professors, and presentations in classes and at student events. A research assistant explained the study before scheduling a participant’s baseline session. At the baseline session, participants completed a computerized survey, underwent randomization, and immediately attended their first resistance session or a control session. Randomization was performed in permuted blocks of two with the use of the online tool Randomize.net, with stratification according to site. All the participants gave written informed consent.

Interventions

The Enhanced Assess, Acknowledge, Act Sexual Assault Resistance program consisted of four 3-hour units that involved information-providing games, mini-lectures, facilitated discussion, and application and practice activities. The first author developed, revised, and pilot-tested the program between 2005 and 2011.23,24 The names (Assess, Acknowledge, and Act) and content of the first three units were based on recommendations by Rozee and Koss for a resistance program for women.25 These authors drew heavily on the work of Ullman regarding successful rape self-defense strategies26 and on Nurius and Norris’s “cognitive ecological” model,27 which provided a theoretical framework for the environmental and psychological factors that affect women’s responses to sexual assault. The fourth unit (Sexuality and Relationships) adapted content from the Our Whole Lives sexuality-education curricula.28,29 Participants assigned to the resistance group could choose to attend sessions for all the units in one weekend (two units each day) or for one unit per week for 4 weeks.

Unit 1 (Assess) focused on improving women’s assessment of the risk of sexual assault by male acquaintances and developing problem-solving strategies to reduce perpetrator advantages. Unit 2 (Acknowledge) assisted women to more quickly acknowledge the danger in situations that have turned coercive, explore ways to overcome emotional barriers to resisting the unwanted sexual behaviors of men who were known to them, and practice resisting verbal coercion. Unit 3 (Act) offered instruction about and practice of effective options for resistance; this unit included 2 hours of self-defense training based on Wen-Do.30 The unit focused on common sexual assault situations involving acquaintances and defense against attackers who were larger than the woman. Unit 4 (Sexuality and Relationships) aimed to integrate content from the previous units into participants’ sexual lives by providing sexual information, including the slang and scientific terms for a wide range of possible sexual activities beyond intercourse and health and safer-sex practices, and a context to explore their sexual attitudes, values, and desires and to develop strategies for sexual communication.

A detailed manual provided instructions for facilitators (see the Supplementary Appendix, available at NEJM.org). Initially, a 10-day training period, which included training in self-defense, was conducted for facilitators. In year 2, because most facilitators were experienced, the training period was shortened to 1 week.

In the control sessions, brochures on sexual assault were displayed; this mimicked common university practice of having brochures available in campus clinics and counseling centers. The selection of brochures was campus-specific; however, the content was similar across sites and included general information on sexual assault and post-rape legal and medical advice (see the Supplementary Appendix). A research assistant informed participants about the brochures and invited them to take them and read them; this assistant also offered to answer questions in the group session, which was scheduled to last 15 minutes, or privately afterward.

All resistance and control sessions were audio-recorded to assess fidelity to the interventions and staff adherence to the procedures and content. One quarter of the recordings from both groups, stratified according to facilitator or research assistant and semester, were randomly selected and scored according to checklists developed from the operations manuals. The mean scores for fidelity to the intervention were 94% (range, 81 to 100) for the resistance sessions and 86% (range, 75 to 100) for the control sessions.

Data Collection

All the participants completed in-person computerized surveys at baseline and 1 week after completion of the intervention (control participants were matched to the same interval but participated in only one session) and offsite Web-based surveys at 6 months and 12 months. To minimize attrition, participants in both groups were contacted by telephone, text, or e-mail at each time point, with up to seven attempts at contact made at each time point. Incentives were provided for completing the baseline and postintervention surveys (psychology-course bonus credit and entry in a $300 lottery) and the follow-up surveys ($30 gift cards). To retain participants in the resistance group during their multiple sessions, additional incentives (small gifts and tickets for two, $25, end-of-session lotteries) were used. Women were considered to be lost to follow-up if they did not complete the survey at 12 months.

Outcome Measures

Information on sexual victimization was collected with the use of the Sexual Experiences Survey–Short Form Victimization (SES-SFV).31 The SES-SFV, a revision of the original 1982 SES,32 is the most widely used measure in sexual assault research and has high reliability and validity.33 Its strength is that it does not require correct labeling of sexual assault by participants but assesses how often particular experiences that legally constitute sexual assault (in Canada) and rape (in the United States) have occurred. For example, one item on the survey reads, “A man put his penis into my vagina, or inserted fingers or objects without my consent by using force, for example holding me down with his body weight, pinning my arms, or having a weapon.”

All experiences reported during 12 months of follow-up were classified into one of five sexual victimization categories: completed rape, attempted rape, coercion, attempted coercion, or nonconsensual sexual contact. The primary outcome was completed rape; other outcomes were prespecified as tertiary. (Secondary outcomes were psychological variables that were expected to mediate the effects of the intervention and are not included here.) Completed rape (oral, vaginal, or anal penetration) and nonconsensual sexual contact (nonpenetrative) were defined as nonconsensual sexual acts in which the perpetrator used threats, force, or drug or alcohol incapacitation. Coercion was considered to have occurred when perpetrators used pressure or manipulation (e.g., “threatening to end the relationship” or “continually verbally pressuring me”) to induce compliance in nonconsensual penetrative sexual acts. Attempted rape and attempted coercion were occasions in which the perpetrator tried to engage in the behavior but was not successful. For completed and attempted rapes, participants recorded the dates of occurrence.

Study-group cross-contamination was measured on follow-up surveys in which participants were asked whether they knew anyone in the other randomized group and, if so, what they shared with (or were told by) that person.

Statistical Analysis

Outcomes were assessed in the modified intention-to-treat population, which included all eligible participants who completed one or more postrandomization survey. The primary analysis compared the incidence (first occurrence) of completed rape between the control group and the resistance group with the use of Kaplan–Meier failure curves (indicating the cumulative percentage of completed rapes among women in the respective groups) and the log-rank test. To account for the correlation among observations within group sessions, variance estimates were appropriately inflated34 for within-session clustering with the use of estimates of the design effect. The benefit of the resistance program was described in terms of relative risk reductions and the number of women who would need to participate in the program to prevent one additional completed rape from occurring within 1 year after participation. Because researchers have speculated that rates of attempted rape might be increased by resistance training,21 the incidence of attempted rape was also assessed.

In other modified intention-to-treat analyses, the incidences of coercion, attempted coercion, and nonconsensual sexual contact were compared between the control group and the resistance group with the use of discrete-time survival analyses that used a complementary log–log regression model,35 in which the variance estimates for within-session clustering were also inflated.36

Two prespecified subgroup analyses were performed to assess whether the resistance program had a similar effect regardless of prior rape victimization and program timing (i.e., weekend vs. weekday sessions); tests for interaction were performed with the use of a Cox proportional-hazards regression model. All P values were two-tailed, and P values of less than 0.05 were considered to indicate statistical significance. All statistical analyses were performed with the use of SAS software, version 9.3 (SAS Institute).