Protocol for a Trial Assessing the Efficacy of a Universal School-Based Prevention Program for Addictive Behaviors

"Juego de Llaves" [ Set of Keys ] is a universal school-based prevention program for adolescents aged 12-15. It is aimed at reducing drug use and other addictive behaviors. This paper describes the full protocol for the evaluation design, instruments, randomization procedure, follow-ups, and primary outcomes.

Non-Randomized Control Cluster Trial in a set of Spanish secondary schools, with follow-ups at 12-, 24- and 36-months. Participants will be allocated to an experimental or control group. Using a digital application designed for the study, a battery of instruments will be used to assess addictive behaviors, sociodemographic variables, school climate and other transdiagnostic psychological variables.

A pilot test will be carried out to test the implementation protocol and to calculate the sample size needed for outcome evaluation. After implementing the program, longitudinal statistical approaches will be used to report intervention efficacy and potential moderators and mediators.

There is a lack of assessments on the effectiveness of school prevention programs, and this paper is expected to improve monitoring and ongoing evaluation in prevention.