Study protocol for a quasi-experimental investigation of the effectiveness of the ‘CATCH My Breath’ vaping prevention curriculum at preventing vaping outcomes among high school students in Ontario, Canada

Vaping is prevalent among youth in Canada, and youth who vape are at risk of becoming addicted to nicotine and continuing to vape. Given these risks, there is a need to identify effective prevention approaches. The goal of this study is to investigate the effectiveness of the ‘CATCH My Breath’ (CMB) vaping prevention curriculum at preventing vaping outcomes among a cohort of high school students in Ontario, Canada. This quasi-experimental study will use a non-equivalent control group pretest-posttest design. A purposive sample of 28 high schools in Ontario, Canada will be recruited, and a trained presenter will deliver the CMB curriculum to grade 9 students during selected classes. CMB is a school-based vaping prevention curriculum with demonstrated success in the United States that incorporates theory to foster social competence and social influence resistance skills. Students in the intervention group will complete online surveys before exposure to the curriculum, and 3- and 12-months later to identify changes in vaping knowledge and attitudes, susceptibility to vaping among non-vapers, vaping initiation, and current vaping. These data will be compared to a matched sample of school- and student-level data from the COMPASS study, an ongoing longitudinal cohort study of youth health behaviours. Descriptive analysis of baseline data will produce a profile of demographics and baseline characteristics and identify any imbalances between the intervention and comparison groups that should be accounted for in later analyses. Multilevel regression models will test for intervention effects while controlling for baseline differences through the use of covariates. To our knowledge, there are no published studies demonstrating that a vaping program can prevent vaping initiation among high school students. As a result, there is not enough evidence for schools to confidently implement programs that address vaping. Given the demand from Canadian high schools for vaping prevention programming, there is a need to further examine the impact of CMB to inform program recommendations to schools. This study has been registered with ClinicalTrials.gov on Feb 7, 2025 (NCT06825338).