PAIRS: Friend-Based AISA Intervention

In this project the investigators will conduct a Phase 2 trial to test the efficacy of a friend-based motivational interview (FMI) compared to a treatment-as-usual (TAU) control, following participants over 1-year post-intervention (Aim 1.). With this trial the investigators also will address some key questions about FMI effects on target attitudes and behaviors (Aim 2.a.) that may be mechanisms of intervention outcome (Aim 2.b.). This includes Instrumental mechanisms (readiness, barriers, and assault protective behavior skills), and the dyadic relationship (closeness, collaboration between the friends in the dyad).

Aim 1. In a Phase 2 trial, the investigators will examine the efficacy of a friend-based motivational intervention (FMI) to reduce AISA risk relative to an active control condition over 1-year post-intervention.

The investigators will compare the FMI to a standard sexual assault prevention intervention widely used on U.S. college campuses. The investigators will use a three-level HLM, with repeated measures over one year (3, 6, 9, 12-month follow-up) nested within person (Level 2), and person nested within dyad (Level 3) to examine AISA outcomes. The investigators expect those in the FMI to report fewer incidences of AISA at follow-up assessments. Both AISA and assaults not involving alcohol will be examined.

Aim 2. Examine mechanisms (instrumental, relationship) of intervention effects. In this dyad-based FMI, an interdependent process may unfold that influences outcomes whereby the FMI influences AISA risk through a person's own change, as well as through their friend's change. It is important to distinguish these two processes as each may be an important part of intervention effects. Accordingly, with longitudinal Actor-Partner Interdependence Models (APIM, Cook \& Kenny, 2005; Kenny \& Ledermann, 2017) the investigators will test whether the intervention impacts mechanisms of change through actor (a person's own change), partner (friend's change) effects, or both (Aims 2a-2c).

Aim 2.a. Examine intervention effects on instrumental and relationships putative mediators, whether the putative predictors predict AISA.

In this aim the investigators will test pathways relevant to the proposed mediational pathways (intervention to mediator, and mediator to outcome).

Aim 2.b. Formally test actor (person's own change) mechanisms (indirect effects). Indirect effects through instrumental (readiness, FAPB skills, and perceived barriers) and relationship (closeness and collaboration) mechanisms will be tested. The investigators expect that the FMI will predict increases in closeness, collaboration, readiness, and FAPB skills, and decreases in perceived barriers, which in turn, will predict declines in AISA.

Aim 2.c. Formally test partner (friend's change) mechanisms (indirect effects). Indirect effects through friend's instrumental (readiness, FAPB skills, and perceived barriers) and relationship (closeness and collaboration) mechanisms will be tested. Because partner effects have not previously been examined, tests of partner effects are viewed as exploratory and no specific hypotheses are offered.

This Phase 2 trial will help to establish the efficacy of an intervention that harnesses the power of friends to address the significant public health problem of campus-based AISA. This study also will shed needed light on the mechanisms and complex nature of dyadic change that occurs in response to such an intervention. Findings will lay the groundwork for Phase 3 work.

• Change in Readiness to Intervene [Срок оценки: This will be completed during Baseline, 1 month follow-up, 3 month follow-up, 6 month follow-up, 9 month follow-up, and 12 month follow-up]
• Change in Peer-Directed Bystander Behaviors Scale for Strangers [Срок оценки: This will be completed during Baseline, 1 month follow-up, 3 month follow-up, 6 month follow-up, 9 month follow-up, and 12 month follow-up]
• Changes to Assault Protective Strategies [Срок оценки: This will be completed during Baseline, 1 month follow-up, 3 month follow-up, 6 month follow-up, 9 month follow-up, and 12 month follow-up]
• Change to Barriers to Sexual Assault Bystander Intervention [Срок оценки: This will be completed during Baseline, 1 month follow-up, 3 month follow-up, 6 month follow-up, 9 month follow-up, and 12 month follow-up]
• Change to Concerns About Intervening [Срок оценки: This will be completed during Baseline, 1 month follow-up, 3 month follow-up, 6 month follow-up, 9 month follow-up, and 12 month follow-up]
• Change to Bystander Intervention Behavior [Срок оценки: This will be completed during Baseline, 1 month follow-up, 3 month follow-up, 6 month follow-up, 9 month follow-up, and 12 month follow-up]