Rachel Laxer

The COMPASS study: a longitudinal hierarchical research platform for evaluating natural experiments related to changes in school-level programs, policies and built environment resources

BackgroundFew researchers have the data required to adequately understand how the school environment impacts youth health behaviour development over time.Methods/DesignCOMPASS is a prospective cohort study designed to annually collect hierarchical longitudinal data from a sample of 90 secondary schools and the 50,000+ grade 9 to 12 students attending those schools. COMPASS uses a rigorous quasi-experimental design to evaluate how changes in school programs, policies, and/or built environment (BE) characteristics are related to changes in multiple youth health behaviours and outcomes over time. These data will allow for the quasi-experimental evaluation of natural experiments that will occur within schools over the course of COMPASS, providing a means for generating “practice based evidence” in school-based prevention programming.DiscussionCOMPASS is the first study with the infrastructure to robustly evaluate the impact that changes in multiple school-level programs, policies, and BE characteristics within or surrounding a school might have on multiple youth health behaviours or outcomes over time. COMPASS will provide valuable new insight for planning, tailoring and targeting of school-based prevention initiatives where they are most likely to have impact.

Reliability and validity of the weight status and dietary intake measures in the COMPASS questionnaire: are the self-reported measures of body mass index (BMI) and Canada's food guide servings robust?

BackgroundThe COMPASS study is designed to follow a cohort of ~30,000 grade 9 to 12 students attending ~60 secondary schools for four years to understand how changes in school characteristics (policies, programs, built environment) are associated with changes in youth health behaviours. Since the student-level questionnaire for COMPASS (Cq) is designed to facilitate multiple large-scale school-based data collections using passive consent procedures, the Cq is only comprised of self-reported measures. The present study assesses the 1-week (1wk) test-retest reliability and the concurrent validity of the Cq measures for weight status and dietary intake.MethodsValidation study data were collected from 178 grade 9 students in Ontario (Canada). At time 1 (T1), participants completed the Cq and daily recoding of their dietary intake using the web-based eaTracker tool. After one week, (T2), students completed the Cq again, participants submitted their daily eaTracker logs and staff measured their height and weight. Test-retest reliability of the self-reported (SR) weight status and dietary intake measures at T1 and T2, and the concurrent validity of the objectively measured and SR weight status and dietary intake measures at T2 were examined using intraclass correlation coefficients (ICC).ResultsTest-retest reliability for SR height (ICC 0.96), weight (ICC 0.99), and BMI (ICC 0.95) are considered substantial. The concurrent validity for SR height (ICC 0.88), weight (ICC 0.95), and BMI (ICC 0.84) are also considered substantial. The test-retest reliability for SR dietary intake for fruits and vegetables (ICC 0.68) and milk and alternatives (ICC 0.69) are considered moderate, whereas meat and alternatives (ICC 0.41), and grain products (ICC 0.56) are considered fair. The concurrent validity for SR dietary intake identified that fruits and vegetables (ICC 0.53), milk and alternatives (ICC 0.60), and grain products (ICC 0.41) are considered fair, whereas meat and alternatives (ICC 0.34) was considered slight.ConclusionsWhile the test-retest reliability of the measures used in this study were all high, the concurrent validity of the measures was considered acceptable. The results support the use of the self-reported COMPASS weight status and dietary intake measures for use in research where objective measures are not possible.

A Cross-sectional Study Examining Factors Associated with Youth Binge Drinking in the COMPASS Study: Year 1 Data

Frequent alcohol use and binge drinking are associated with numerous negative health outcomes. Using data from 17,497 grade 9 to 12 students participating in the COMPASS Study (Year 1), we examined the factors associated with current alcohol use and current binge drinking. Overall, 38.4% of students were considered current alcohol users and 25.5% were current binge drinkers. Tobacco or marijuana use, bullying others, weekly spending money, ethnicity, and grade were associated with increased likelihood of current alcohol use and current binge drinking. It is evident that a substantial number of youth in the Year 1 COMPASS sample report frequently using alcohol and in volumes considered harmful to their health. Considering that numerous risk factors were found to predict alcohol use and binge drinking, future research should evaluate the impact of tailoring interventions to change the modifiable factors associated with high-risk drinking or targeting interventions to at-risk youth.

Clustering of risk-related modifiable behaviours and their association with overweight and obesity among a large sample of youth in the COMPASS study

BackgroundCanadian youth exhibit a number of risky behaviours, some of which are associated with overweight and obesity. The purpose of this study was to examine the prevalence of 15 modifiable risk behaviours in a large sample of Canadian youth, to identify underlying subgroups based on patterns of health behaviours, and to examine the association between identified subgroups and overweight/obesity.MethodsData from 18,587 grades 9–12 students in Year 1 (2012–13) of the COMPASS study and latent class analysis were used to identify patterns and clustering among 15 health behaviours (e.g., physical inactivity, sedentary behaviour, unhealthy eating, substance use). A logistic regression model examined the associations between these clusters and overweight/obesity status.ResultsFour distinct classes were identified: traditional school athletes, inactive screenagers, health conscious, and moderately active substance users. Each behavioural cluster demonstrated a distinct pattern of behaviours, some with a greater number of risk factors than others. Traditional school athletes (odds ratio (OR) 1.15, 95% CI 1.03–1.29), inactive screenagers (OR 1.33; 1.19–1.48), and moderately active substance users (OR 1.27; 1.14–1.43) were all significantly more likely to be overweight/obese compared to the health conscious group.ConclusionsFour distinct subpopulations of youth were identified based on their patterns of health and risk behaviours. The three clusters demonstrating poorer health behaviour were all at an increased risk of being overweight/obese compared to their somewhat healthier peers. Obesity-related public health interventions and health promotion efforts might be more effective if consideration is given to population segments with certain behavioural patterns, targeting subgroups at greatest risk of overweight or obesity.

An analysis of weight perception and physical activity and dietary behaviours among youth in the COMPASS study

Purpose Weight misperceptions appear common among youth, potentially influencing their motivation to engage in health-related behaviours; however, the direction of impact remains unclear. The current study examined how weight perception influences physical activity (PA) and diet among youth. Methods This study used 2-year linked data of 19,322 grade 9–12 students from Year 2 (Y2:2013-2014) and 3 (Y3:2014-2015) of the COMPASS study. Generalized Estimating Equation models tested the effect of Y3 weight perception on the various Y3 PA and dietary behaviour measures, adjusting for Y3 covariates (grade, race/ethnicity, weekly spending money), school cluster, school area median household income, and the Y2 outcome. Models were stratified by gender and body mass index (BMI) classification. Results Regardless of BMI status, overweight perceptions among boys and girls were associated with lower likelihoods of playing school sports, physical education class enrollment, meeting resistance exercise recommendations, eating breakfast regularly, and less vigorous-intensity PA, and among boys only, lower odds of meeting PA guidelines, compared to their peers who perceived their weight as “about right”. In boys with normal-weight BMIs, underweight perceptions predicted less vigorous-intensity PA, and lower odds of physical education class enrollment, and of meeting PA and resistance exercise recommendations, than “about right” perceptions. Among girls, underweight perceptions predicted lower likelihoods of engaging in adequate resistance exercise and playing intramurals, and greater odds of eating fast food on weekends, purchasing snacks, and drinking energy drinks and sugar-sweetened beverages. Girls with overweight/obese BMIs who perceived their weight as such were less likely to consume adequate fruits and vegetables relative to their counterparts with “about right” weight perceptions. Conclusions Overall, weight perceptions of “about right” appear more favourable for health behaviours among youth across the weight range. Results suggest obesity prevention strategies aiming to increase awareness of weight status may have unintended effects.

Behavioural patterns only predict concurrent BMI status and not BMI trajectories in a sample of youth in Ontario, Canada

Background Youth are engaging in multiple risky behaviours, increasing their risk of overweight, obesity, and related chronic diseases. The objective of this study was to examine the effect of engaging in unique clusters of unhealthy behaviours on youths’ body mass index (BMI) trajectories. Methods This study used a linked-longitudinal sample of Grades 9 and 10 students (13 to 17 years of age) participating in the COMPASS host study. Students reported obesity-related and other risky behaviours at baseline and height and weight (to derive BMI) at baseline (2012/2013) and annually for 2 years post-baseline (2013/14 and 2014/15). Students were grouped into behavioural clusters based on response probabilities. Linear mixed effects models, using BMI as a continuous outcome measure, were used to examine the effect of engaging in clusters of risky behaviours on BMI trajectories. Results There were significant differences in BMI of the four behavioural clusters at baseline that remained consistent over time. Higher BMI values were found among youth classified at baseline to be Typical High School Athletes (β = 0.232 kg/m2, [confidence interval (CI): 0.03–0.50]), Inactive High Screen-User (β = 0.348 kg/m2, CI: 0.11–0.59) and Moderately Active Substance Users (β = 0.759 kg/m2, CI: 0.36–1.15) compared to students classified as Health Conscious. Despite these baseline differences, BMI appeared to increase across all behavioural clusters annually by the same amount (β = 0.6097 kg/m2, (CI) = 0.57–0.64). Conclusions Although annual increases in BMI did not differ by behavioural clusters, membership in a particular behavioural cluster was associated with baseline BMI, and these differences remained consistent over time. Results indicate that intervening and modifying unhealthy behaviours earlier might have a greater impact than during adolescence. Health promotion strategies targeting the highest risk youth as they enter secondary school might be promising means to prevent or delay the onset of obesity.

The association of school connectedness and bullyinginvolvement with multiple screen-time behaviours amongyouth in two Canadian provinces: a COMPASS study

INTRODUCTION Screen time, a proxy for sedentary behaviours, has emerged as a critical health determinant among youth in contemporary societies, where most aspects of youth life involve access to screen-time devices. An understudied approach to reducing screen time among youth is bullying reduction. This study aims to understand the association between bullying perpetration, victimization, youth perception of the school environment and multiple screen-time behaviours. METHODS A total of 44,861 youth aged between 13 and 18 years in two Canadian provinces completed a validated questionnaire that collected student data on health behaviours and outcomes, including multiple screen-time behaviours, bullying perpetration and victimization, and school connectedness. The outcome variables were total screen time, time spent watching television, playing video games, internet surfing, and communication- based screen-time behaviours. Using a random intercept, the final models were built using PROC MIXED in SAS 9.4. These models were adjusted for age, ethnicity, weekly disposable income, daylight hours, and weather variables. RESULTS Compared to youth who reported non-involvement in bullying, youth who were bullies, victims, or both bullies and victims spent on average more minutes per day in front of screens across all screen time categories. Youth who felt happy and safe at school, and who perceived their teachers as being fair, reported lower levels of multiple screen-time behaviours. CONCLUSION With non-involvement in bullying showing a strong negative association with multiple screen-time behaviours, school policies to address bullying and screen time through school connectedness could offer a novel approach in minimizing these harmful behaviours.

Do school physical activity policies and programs have a role in decreasing multiple screen time behaviours among youth

Screen time in youth has been associated with a wide range of poor health outcomes. Evidence indicates the need to develop physical activity (PA) school policies and programs that are aimed at decreasing youth screen time behaviours. This study aims to understand the association between PA policies and programs embedded into the functioning of 89 schools across two provinces in Canada and multiple screen time behaviours. As part of the COMPASS Study, a total of 44,861 youth aged between 13 and 18years and belonging to 89 schools in two Canadian provinces completed a validated questionnaire for health behaviours and outcomes data. PA policies and programs were measured using the School Policies and Practices Questionnaire, completed by the relevant school administrator. Participation in before-school, noon hour, or after-school intramural programs, participation in varsity sports, and access to indoor areas of PA during non-instructional time, was associated with significantly lower multiple screen time behaviours across both provinces. With exposure to multiple electronic and digital devices only predicted to increase among youth in the future, there is a need to conceptualize and integrate school-based screen time reducing PA policies and programs into the regular functioning of the schools.