Introduction
HIV or substance use, substance abuse
South Africa bears the largest HIV burden of any country in the world [Rates of interpersonal violence are extremely high in South Africa, particularly among young men, where in 2007, the homicide victimization rate among men aged 15–24 was 184/100,000 population [While men are clearly at risk for HIV, global attention has focused on interventions for women [To address these challenges, we designed a behavioral intervention using soccer to engage men in an intervention that is compatible with their identities, roles, and crucially, to reduce the cluster of risks—substance use, risky sexual behavior, violence, and unemployment—associated with HIV [In order to examine the innovative soccer intervention, this trial needed to address multiple outcomes concurrently. Improving one outcome (e.g., reducing substance abuse) was unlikely to impact the incidence of HIV or substance use. We created an intervention that addressed multiple concurrent problems. Given that there were multiple outcomes, we needed to consider the probability of Type 1 error. Based on initial power analyses, we estimated that we needed to observe a minimum of three significant outcomes in order to identify the intervention strategy as efficacious.