Trans-adaption of successful cigarette smoking intervention to randomised school-based cannabis intervention trial

Despite the emergence of cannabis use as a public health issue of significance in the 21st Century, no school-based interventions specifically addressing cannabis use have been reported in the literature. The prevalence of adolescent cannabis use has risen during the 1990s while the age of onset has decreased. This three-year trial seeks to trans-adapt a successful school-based cigarette smoking program underpinned by harm minimisation (HM) theory (including abstinence messages), into a school-based cannabis intervention trial. This innovative intervention will be compared to the largely abstinence-based drug use prevention activities currently used in W A. The first and second years of the project have been successful in establishing and conducting this school-based cluster randomised control trial. In summary, under the direction of an experienced management team, the project has recruited 24 Perth metropolitan high schools - the required number to provide sufficient power to detect hypothesised differences between intervention and comparison students. Within these schools, active parental consent to participate in data collection for the project was obtained from over 3,300 students after the initial letter and two reminders to parents (69% consent rate). Baseline data were collected from nearly 3,100 students (93% of those eligible), 2953 students at post-test 1 and 2701 students at the end of the second year of intervention (Post-test 2). In addition, data were collected at each of these time points from English and Health Education teachers, and school principals