Internet-Based Universal Prevention for Students and Parents to Prevent Alcohol and Cannabis Use Among Adolescents: Protocol for the Randomized Controlled Trial of Climate Schools Plus

BACKGROUND: Early initiation of alcohol and cannabis use markedly increases the risk of harms associated with use, including the development of substance use and mental health disorders. To interrupt this trajectory, effective prevention during the adolescent period is critical. Despite evidence showing that parents can play a critical role in delaying substance use initiation, the majority of prevention programs focus on adolescents only. Accordingly, the Climate Schools Plus (CSP) program was developed to address this gap. OBJECTIVE: This paper outlines the protocol for a cluster randomized controlled trial (RCT) of the CSP program, a novel internet-based program for parents and students to prevent adolescent substance use and related harms. The CSP program builds on the success of the Climate Schools student programs, with the addition of a newly developed parenting component, which allows parents to access the internet-based content to equip them with knowledge and skills to help prevent substance use in their adolescents. METHODS: A cluster RCT is being conducted with year 8 students (aged 12-14 years) and their parents from 12 Australian secondary schools between 2018 and 2020. Using blocked randomization, schools are assigned to one of the two groups to receive either the CSP program (intervention) or health education as usual (control). The primary outcomes of the trial will be any student alcohol use (≥1 standard alcoholic drink/s) and any student drinking to excess (≥5 standard alcoholic drinks). Secondary outcomes will include alcohol- and cannabis-related knowledge, alcohol use-related harms, frequency of alcohol consumption, frequency of drinking to excess, student cannabis use, parents’ self-efficacy to stop their children using alcohol, parental supply of alcohol, and parent-adolescent communication. All students and their parents will complete assessments on three occasions—baseline and 12 and 24 months postbaseline. In addition, students and parents in the intervention group will be asked to complete program evaluations on two occasions—immediately following the year 8 program and immediately following the year 9 program. RESULTS: Analyses will be conducted using multilevel, mixed-effects models within an intention-to-treat framework. It is expected that students in the intervention group will have less uptake and excessive use of alcohol compared with the students in the control group. CONCLUSIONS: This study will provide the first evaluation of a combined internet-based program for students and their parents to prevent alcohol and cannabis use. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12618000153213; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374178 (Archived by WebCite at http://www.webcitation.org/71E0prqfQ) REGISTERED REPORT IDENTIFIER: RR1-10.2196/10849