How did Project Northland reduce alcohol use among young adolescents? Analysis of mediating variables

Project Northland is a randomized trial designed to create, implement and evaluate multilevel, community-wide strategies to prevent alcohol use among adolescents. This paper will focus on the mediating outcomes of the early adolescent phase of Project Northland when the students in the study cohort were in Grades 6-8. The project was conducted in 24 school districts and adjacent communities in northeastern Minnesota. The intervention consisted of social-behavioral curricula in schools, peer leadership activities, parental involvement and education, and community-wide activities. At the end of 3 years of intervention, significantly fewer students in the intervention school districts reported alcohol use than students in the reference districts. Mediation analyses were conducted to investigate if the intervention's effects on mediating variables could explain the reduction in alcohol use. Important mediators of Project Northland's effect on alcohol use were: (1) peer influence to use, including normative estimates, (2) functional meanings of alcohol use, (3) attitudes and behaviors associated with alcohol and drug problems like stimulus seeking, rule violations and bad judgement, and (4) parent-child alcohol-related communication around alcohol use. In addition, among those who did not use alcohol at baseline, self-efficacy to refuse offers of alcohol was a significant mediator.