Vapes (also called e-cigarettes) have increased in popularity among youth in Canada and the United States. Youth who try vaping are at risk of becoming addicted and continuing to vape. To help combat the rise in vaping, there is an urgent need to identify effective ways to prevent youth from experimenting with vaping. Because of the novelty of vapes, there are few school-based programs targeting vaping. This study will investigate whether a vaping prevention curriculum called 'CATCH My Breath' (CMB) prevents high school students from starting to vape.

The investigators will recruit 28 schools in Ontario, Canada into the intervention group, and students at these schools will be presented with the CMB curriculum by Public Health Unit staff. CMB is an evidence-based program that includes two 60-minute lessons that provide students with information about social norms related to vaping, health risks of vaping, media literacy, and in-class activities to practice refusal skills. Students will complete an online survey before being exposed to the curriculum, 3-months later, and 12-months later. The vaping behaviours of these students will be compared to students in a separate study of youth health (i.e., the COMPASS study) who are not given the curriculum.

Evidence from this study will identify whether students exposed to CMB are less likely to start and continue vaping. If effective, CMB can be easily delivered in high schools across Canada in order to reduce the number of students who vape.

Background and Importance: Youth vaping (or e-cigarette use) as increased dramatically among youth populations in Canada and the United States. While the long-term negative effects of vaping are relatively unknown, youth who vape are at risk of becoming addicted to nicotine and continuing to vape. Given the novelty of these devices and their rising popularity among youth, there is an urgent need to identify effective prevention approaches.

Research Aims: The goal of this study is to investigate the effectiveness of the 'CATCH My Breath' (CMB) vaping prevention curriculum at preventing vaping initiation among a cohort of high school students in Ontario, Canada. Specifically, this study will identify whether students exposed to CMB have a lower likelihood of 1) initiating vaping, 2) being susceptible to future vaping, and 3) vaping in the past 30-days at 12-month follow-up, compared to a matched comparison group of students. This study will also investigate whether the effects of the intervention differ according to gender. Methods: Intervention. CMB is a school-based vaping prevention curriculum based on best practices from earlier prevention studies and incorporates theory to foster social competence and social influence resistance skills. It is delivered through two 60-minute lessons delivered by a trained presenter. A pilot study identified components of the program that worked well and what needed to be adapted for a Canadian high school context. Sample. A purposive sample of 28 high schools in Ontario will be recruited and Public Health staff will deliver the curriculum to grade 9 students during Physical Education & Health classes. A matched sample of 28 high schools from a larger pool of schools participating in a separate study of youth health (i.e., the COMPASS study) will be selected as a comparison group. A matched sample of students will be identified from comparison group schools. Data collection & analysis. Students in the intervention group (n=2800) will complete an online survey before exposure to the curriculum and 3-months, and 12-months later to identify changes in vaping knowledge, attitudes, and behaviour. 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. Expected Outcomes: Evidence from this project will identify whether students exposed to CMB are less likely to start vaping, which will support school-based efforts to prevent vaping initiation and experimentation among youth.

School Inclusion Criteria:

• public and private schools in Ontario, English-speaking schools, include students in grades 9 through 12, operate in a standard school/classroom setting (i.e., not a virtual school)

School Exclusion Criteria:

• non-English speaking schools, virtual schools, currently using the CATCH My Breath vaping prevention curriculum

Student Inclusion Criteria:

• enrolled in the class in which the CATCH My Breath curriculum is being delivered

Student Exclusion Criteria:

• not enrolled in the class in which the CATCH My Breath curriculum is being delivered

Student surveys: Anonymized data for students who have given permission for their data to be used for secondary research purposes and the associated Codebook will be uploaded to Borealis to be stored indefinitely at the end of the project following data analysis and publication. These anonymized data will be available only to specific individuals upon request. The requests will be reviewed and approved by the PI.

Field Notes Survey: Anonymized data and the associated Codebook will be uploaded to Borealis to be stored indefinitely at the end of the project following data analysis and publication. These anonymized data will be available only to specific individuals upon request. The requests will be reviewed and approved by the PI.

COMPASS data: Electronic data used for secondary data analysis will not be shared. Those interested in accessing COMPASS data can submit a Data Request Application to the PI of the COMPASS study.

IPD and supporting information will be uploaded to Borealis following data analysis and publication and will be stored indefinitely.

Anonymized data for students who have given permission for their data to be used for secondary research purposes will be available only to specific individuals upon request. The requests will be reviewed and approved by the PI.