Enrollment and assessment of a first-year college class social network for a controlled trial of the indirect effect of a brief motivational intervention

Heavy drinking and its consequences among college students represent a serious public health problem, and peer social networks are a robust predictor of drinking-related risk behaviors. In a recent trial, we administered a Brief Motivational Intervention (BMI) to a small number of first-year college students to assess the indirect effects of the intervention on peers not receiving the intervention. Objectives: To present the research design, describe the methods used to successfully enroll a high proportion of a first-year college class network, and document participant characteristics. Methods: Prior to study enrollment, we consulted with a student advisory group and campus stakeholders to aid in the development of study-related procedures. Enrollment and baseline procedures were completed in the first six weeks of the academic semester. Surveys assessed demographics, alcohol use, and social network ties. Individuals were assigned to a BMI or control group according to their dormitory location. Results: The majority of incoming first-year students (1342/1660; 81%) were enrolled (55% female, 52% nonwhite, mean age 18.6 [SD = 0.51]). Differences between the intervention and control group were noted in alcohol use, but were in large part a function of there being more substance-free dormitory floors in the control group. Conclusions: The current study was successful in enrolling a large proportion of a first-year college class and can serve as a template for social network investigations.