Youth perception of difficulty accessing cannabis following cannabis legalization and during the early and ongoing stages of the COVID-19 pandemic: repeat cross-sectional and longitudinal data from the COMPASS study.

Background: Very little research has examined how perceptions of cannabis access among underage youth in Canada have changed since cannabis was legalized and since the onset of the COVID-19 pandemic. As such, this paper examines the effect of the early and ongoing stages of the COVID-19 pandemic period on youth perceptions of cannabis access over time since the onset of the Cannabis Act in 2018 in a large sample of Canadian youth.

Methods: Using data from the COMPASS study (T1:2018/19, T2:2019/20, T3:2020/21), we used both repeat cross-sectional data [T1 (n = 38,890), T2 (n = 24,109), and T3 (n = 22,795)] to examine overall trends in perceptions of cannabis access, and sequential cohort longitudinal data [n = 4,677 students linked from T1 to T3] to examine the differential changes in perceptions of cannabis access among students over time.

Mental health and cannabis use among Canadian youth: Integrated findings from cross-sectional and longitudinal analyses.

Background And Purpose: Using data from two methodologically independent youth research studies in Canada, the Health Behaviour in School-aged Children (HBSC) study and the Cannabis, Obesity, Mental health, Physical activity, Alcohol, Smoking, and Sedentary behaviour (COMPASS) study, the objective of this study was to compare associations between youth's mental health and cannabis use across samples. Using similar indicators in both studies, our goal was to affirm the potential for nationally representative cross-sectional analyses (HBSC) to replicate findings found in a longitudinal non-representative data source (COMPASS), enhancing opportunity for causal inferences.

Methods: Data were collected from grade 9 and 10 Canadian students participating in the 2017/18 HBSC (n=8462) and 2017/18 to 2018/19 waves of COMPASS (n=32,023).

The association between public health engagement in school-based substance use prevention programs and student alcohol, cannabis, e-cigarette and cigarette use.

Objective: This study examined the associations between public health engagement (PHE) in school-based substance use prevention programs and student substance use. For the purposes of this study, PHE refers to any form of collaboration between the local government public health agency and the school to promote the physical and mental health of students.

Methods: Data for this study were collected from the Cannabis, Obesity, Mental health, Physical activity, Alcohol use, Smoking and Sedentary behaviour (COMPASS) study during the 2018/2019 data collection year.

Examining the role that weight perception and social influences have on mental health among youth in the COMPASS study.

Purpose: We investigated whether social health mitigates the association between weight perception and anxiety and depression 1 year later in a large sample of Canadian youth in a prospective, gender-specific analysis.

Methods: We used 2 years of linked survey data from 20,485 grade 9-11 students who participated in wave 6 (2017/18) and 7 (2018/19) of the COMPASS study. Mental health outcomes included the Generalized Anxiety Disorder-7 item (GAD-7) scale and the 10-item Centre for Epidemiological Studies Depression Scale Revised (CESD-10-R).

Patterns of Cannabis Use among Canadian Youth over Time; Examining Changes in Mode and Frequency Using Latent Transition Analysis.

Historically substance use literature has focused on smoking as the main mode of cannabis consumption, so there are knowledge gaps surrounding current understanding of edibles and vaping. These alternative modes of cannabis use are already common among Canadian youth; however, little is known about how these cannabis use patterns change over time. This study examined the mode (smoking, eating/drinking, vaping) and frequency of cannabis use among a large sample of Canadian youth who participated in 2017-2018 and 2018-2019 data collection waves of the COMPASS study.

Correction: An examination of the prospective association between physical activity and academic achievement in youth at the population level.

[This corrects the article DOI: 10.1371/journal.pone.

The Impact of Changes in Physical Education Class Enrollment on Moderate-to-Vigorous Physical Activity Among a Large Sample of Canadian Youth.

Background: Few youth engage in sufficient daily moderate-to-vigorous physical activity (MVPA), and the likelihood of meeting guidelines declines through secondary school. Physical education (PE) can afford youth with opportunities for MVPA. Therefore, the purpose of this study was to investigate the impact of changes in PE enrollment on MVPA and MVPA guideline adherence in Ontario and Alberta secondary students.

Examining Engagement With Public Health in the Implementation of School-Based Health Initiatives: Findings From the COMPASS Study.

Background: Adolescence coincides with the adoption of health behaviors that schools are not necessarily equipped to properly address. Collaboration between schools and external health services such as public health could fill gaps in addressing student health.

Methods: The current study uses student- and school-level survey data from 59 nonprivate secondary schools in Ontario, Canada in year 6 (2017-2018) of the COMPASS study to examine barriers to improving student health, and analyze the effect of public health engagement on student health behaviors.

An examination of the prospective association between physical activity and academic achievement in youth at the population level.

Exercise has significant benefits for brain health and this may have downstream learning benefits for youth. However existing studies looking at links between physical activity and academic achievement are limited by relatively small sample sizes and/or cross-sectional designs. The objective of this study is to determine the direction and magnitude of the association between physical activity and academic achievement in a large prospective sample of adolescents.

High School Intramural Participation and Substance Use: A Longitudinal Analysis of COMPASS Data.

There is an association between sports participation and substance use. However, there is some evidence that intramural sports in high school may not have the same effect. Therefore, the objective of this research was to examine the longitudinal associations between intramural participation in high school and substance use.

A School-Level Examination of the Association between Programs and Policies and Physical Activity Outcomes among Females from the COMPASS Study.

(1) The majority of Canadian youth are not meeting physical activity guidelines, and more female than male youth are falling short of these recommendations. School programs and policies are a viable strategy to improve youth physical activity. However, they may differentially affect female and male activity.

High school sport participation and substance use: A cross-sectional analysis of students from the COMPASS study.

Introduction: The objective of this study was to examine the association between participation in school sports and substance use behaviors in both male and female high school students.

Methods: The current study used cross-sectional data from 60,601 students from Year 6 (2017-2018) of the COMPASS study. Students reported their school physical activity participation (none, intramurals only, varsity only, both) and past 30-day substance use (binge drinking, cannabis use, cigarette use, e-cigarette use).

A cross-sectional examination of the association between co-ed and gender-specific school intramural programs and intramural participation among a sample of Canadian secondary school students.

Intramurals are an important part of the physical activity offerings in secondary schools; however, it is not well understood how co-ed and gender-specific intramural programs impact intramural participation among male and female students. Therefore, the objective of this research was to examine if the number of co-ed, male-only, and female-only intramurals offered at a school was associated with student participation in intramurals. A large sample of Canadian secondary school students (N = 59,370) completed the COMPASS survey in 2017-2018.

Environmental Factors of Youth Milk and Milk Alternative Consumption.

The objective of this research was to determine the school and community characteristics associated with milk and milk alternative (MMA) consumption by Canadian youth. We analyzed self-reported data from 50,058 Canadian students participating in the 2017-2018 wave of the COMPASS survey. We used logistic and linear regression analyses to identify school- and community-level factors associated with students meeting the MMA guidelines, and factors associated with daily number of MMA servings consumed, respectively.

Trends in youth e-cigarette and cigarette use between 2013 and 2019: insights from repeat cross-sectional data from the COMPASS study.

Objectives: E-cigarettes are an increasingly popular product among youth in Canada. However, there is a lack of long-term data presenting trends in use. As such, the objective of this study was to examine trends in e-cigarette and cigarette use across various demographic characteristics between 2013 and 2019 among a large sample of secondary school youth in Canada.

Longitudinal associations between bullying and alcohol use and binge drinking among grade 9 and 10 students in the COMPASS study.

Objectives: Adolescents involved in bullying are at increased risk for alcohol use; however, much of this research has been cross-sectional. The aim of this work was to therefore examine the longitudinal associations between bullying and future alcohol use.

Methods: Data were drawn from the COMPASS study.

Examining the impact of timing of alcohol use initiation on changes to body weight and weight status among students in the COMPASS study.

Obesity rates among Canadian youth continue to be a concern, as weight issues during adolescence can transfer into adulthood, leading to long-term health problems. Current evidence lacks a consistent relationship between alcohol consumption and weight gain, and there remains a paucity of research examining the effect of alcohol intake on body weight and BMI over time. This study seeks to examine the effect of grade when students are first classified as "current drinker" and "current binge drinker" on weight and weight status (BMI) trajectories.

An examination of how age of onset for alcohol, cannabis, and tobacco are associated with school outcomes in grade 12.

Introduction: Youth substance use prevention is a key public health priority. There is evidence that delaying substance use can improve health outcomes. While substance use is associated with negative outcomes at school, the benefits of delaying substance use on these outcomes are less well understood.

An examination of how age of onset for alcohol, cannabis, and tobacco are associated with physical activity, screen time and BMI as students are preparing to graduate from high school.

Introduction: In this study we examined the co-occurrence of alcohol, cannabis, and tobacco among a large cohort of grade 12 students in Canada, and then explored if the age of initiation of these substances was associated with moderate-to-vigorous physical activity (MVPA), screen time, and BMI.

Methods: This cross-sectional study used student-level data from grade 12 students in years 1 to 5 (2012-2016) of the COMPASS study. Random intercept linear regression models were used to examine the impact of age of initiation of alcohol, cannabis, and tobacco use on student average daily physical activity, daily screen time and BMI.

Estimating how extra calories from alcohol consumption are likely an overlooked contributor to youth obesity.

Introduction: Youth obesity rates in Canada continue to rise. In this study, we produced conservative estimates of the potential excess calories from alcohol use across different alcohol consumption patterns common among Canadian youth to assess whether alcohol use should be considered in future obesity prevention strategies.

Methods: Using data from 10 144 Grade 12 students participating in the COMPASS study (2013/14), we estimated the number of calories consumed per year from alcohol consumption.