Optimizing the scientific yield from a randomized controlled trial (RCT): evaluating two behavioral interventions and assessment reactivity with a single trial.

Randomized controlled trials (RCTs) remain the gold standard for evaluating intervention efficacy but are often costly. To optimize their scientific yield, RCTs can be designed to investigate multiple research questions. This paper describes an RCT that used a modified Solomon four-group design to simultaneously evaluate two, theoretically-guided, health promotion interventions as well as assessment reactivity. Recruited participants (N = 1010; 56% male; 69% African American) were randomly assigned to one of four conditions formed by crossing two intervention conditions (i.e., general health promotion vs. sexual risk reduction intervention) with two assessment conditions (i.e., general health vs. sexual health survey). After completing their assigned baseline assessment, participants received the assigned intervention, and returned for follow-ups at 3, 6, 9, and 12 months. In this report, we summarize baseline data, which show high levels of sexual risk behavior; alcohol, marijuana, and tobacco use; and fast food consumption. Sexual risk behaviors and substance use were correlated. Participants reported high satisfaction with both interventions but ratings for the sexual risk reduction intervention were higher. Planned follow-up sessions, and subsequent analyses, will assess changes in health behaviors including sexual risk behaviors. This study design demonstrates one way to optimize the scientific yield of an RCT.