Public Health Sciences (School of)

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This is the collection for the University of Waterloo's School of Public Health Sciences. The School was known as the Department of Public Health and Health Systems until January 2021.

Research outputs are organized by type (eg. Master Thesis, Article, Conference Paper).

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Now showing 1 - 20 of 446

Using Artificial Intelligence for Some Activity Recognition and Anomaly Identification Using a Multi-Sensor Based Smart Home System
(University of Waterloo, 2025-06-09) Saragadam, Ashish
Ambient Assisted Living (AAL) research frequently contends with limitations including reliance on supervised data, lack of personalization and interpretability, and evaluations in artificial laboratory settings. This study aimed to address these gaps by developing an unsupervised, personalized, and interpretable AAL system using low-cost sensors for long- term, real-world activity recognition and behavioural anomaly detection. A multi-modal sensor network (including contact, vibration, outlet, air quality sensors) was deployed in a single participant’s apartment for over 90 days. Primarily unsupervised machine learning techniques, augmented with interpretability methods (SHAP), were used to identify key ac- tivities (cooking, couch-sitting, showering) and detect personalized behavioural deviations. Minimally supervised approaches for showering detection were also accurately achieved using humidity data to address the shortcomings of unsupervised showering model. More importantly, the system effectively identified interpretable anomalies demonstrating the model’s capability to learn the individual’s normal behaviour in the home and identify anomalies, representing significant deviations from the participant’s established routines. In addition, the model was also able to be interpretable that allowed for the participant to understand why each anomaly occured. This study confirms the feasibility of leveraging unsupervised, interpretable methods with affordable sensors for personalized, ecologically valid AAL, significantly reducing labelling dependence and enhancing system trustworthi- ness for scalable, unobtrusive health monitoring.
Developing tools to support older adults during climate-related emergencies
(University of Waterloo, 2025-05-22) Betini, Gustavo
What makes a person more likely to experience adverse health outcomes caused by extreme weather events? Can we identify those individuals at high risk before an extreme event happens? Natural hazards can lead to death and physical injury, as well as non-specific psychological distress, post-traumatic stress disorder, depression, and anxiety. By now, we have a good understanding of the main outcomes and some group-level risk factors associated with these events, such as low socioeconomic status, certain health conditions, and older age. These risk-factors are often used to develop vulnerability indices that can identify people at risk of adverse outcomes during an extreme event. However, these indices can be highly inefficient because not all individuals within each group live with the same vulnerability. Thus, it is essential that we use real-time, clinical, and demographic information to identify individuals at risk before an extreme weather event happens instead of relying on general group membership. The goals of this thesis are a) to understand the risk and protective factors that place older adults at higher risk of adverse health outcomes caused by natural hazards, and b) to develop indices to identify those individuals at highest risk. To achieve these goals, the thesis uses clinical assessments and focuses on acute, short-term health complications often a result of heat-related events and wildfire smokes. The thesis is divided in 3 studies and all studies used data from the interRAI Home Care and interRAI Contact Assessment instruments, which are comprehensive assessments to evaluate the person’s health needs and strengths. Study 1 is an empirical investigation of the risk factors that place older adults at odds of living in homes with inadequate heating or cooling. The study uses longitudinal data and generalized estimating equations to explore risk factors such as demographic and social-economic characteristics as well as availability and quality of informal caregiver support for older adults with complex medical needs in Canada. These factors were used to identify geographic locations in Ontario with high percentages of home care clients living with inadequate heating or cooling at home. This is the first study that addresses the risks and protective factors associated with the thermal environment in home care clients, which is a population at high risk of adverse health outcomes during heat waves and cold spells. Study 2 presents a new index to identify individuals that could be at risk of health complications during extreme weather events. The Brief Risk Index (BRI) was derived from data elements present in a screener that supports home care intake from community and hospital. It focuses on items indicating that individuals receiving home care services would have difficulty evacuating their homes during a time of crisis (e.g., cognitive impairment and difficulty performing activities of daily living). When compared with another tool that has been used in real-life situations, the BRI showed similar performance but with less items. This is the first index that targets the whole home care population in Canada, not only those receiving long-term services. Therefore, the BRI can be a game changing in emergency preparedness because of its efficiency and large target population. Study 3 uses a similar approach as in Study 2 but focuses on home care clients at high risk of health complications caused by poor air quality. While the BRI is a more general tool, the Cardiorespiratory Vulnerability index (CRV) contains 16 items from a standardized assessment for home care clients and includes clinical characteristics often associated with negative health outcomes caused by poor air quality, such respiratory and heart diseases. This is the first index related to risks associated with air quality available in vulnerable populations in Canada, and one of the few worldwide. The study makes an important contribution to public health because climate change is accelerating the conditions under which wildfires and their adverse effects on air quality are more likely to happen. Identifying individuals at high risk before an extreme weather event happens is a pressing problem in our society. This is particularly important today because of our aging population combined with the increase of the frequency, duration, and severity of extreme weather events caused by climate change. This thesis advances our knowledge of the risk and protective factors associated with extreme weather events and provides ready-to-use predictive tools to identify individuals that are more likely to experience health complications. The indices developed here can also be used to identify regions (neighborhoods) with higher concentration of people at risk, meaning that long-term, climate adaptation programs can be applied not only for individuals but also for geographic regions. Thus, the results from the three studies in this thesis represent a unique perspective in how our public health system could prepare for climate change, avoid negative outcome to vulnerable populations and show new directions for research.
Examining the Association Between Climate Worry and Psychological Distress in Canadian Youth
(University of Waterloo, 2025-05-01) Coulis, Sydney
Young people are highly susceptible to the development of mental illnesses, which may be measured through psychological distress scores. Mental illnesses in youth may vary by gender as cis-gendered girls and gender minorities are more likely to experience mental illnesses than their cis-gendered boy counterparts. Within Canada, one in four youth meet the diagnostic criteria for a mental illness regardless of gender. While effects of climate change and associated health outcomes are experienced by diverse populations, these outcomes are particularly concerning pertaining to youth as they will inherit the environment in its current state. One factor that may be associated with increases in psychological distress is that of climate worry: the feelings of worry or fear associated with the ongoing climate change crisis. However, climate worry remains a novel topic with limited existing literature. For youth, climate worry may result in negative emotions including worry, fear, or sadness attributed to their concern for the worsening global climate. Youth are likely to access information regarding climate change through online channels, prompting interest in screen time as a covariate. Climate worry may also be associated with difficulties in focus on daily tasks and may impact sleep due to excessive worry, as well as causing a sense of responsibility to “act.” These concerns are measured through the climate worry section of the Compass Questionnaire. The objective of this thesis was to examine whether climate worry is associated with psychological distress among youth in the COMPASS Study, and whether selected covariates impact this association using linear regression modelling. This thesis used data from the 2022/23 Compass Study cohort of 31,042 high school students from across Alberta, British Columbia, Ontario, Prince Edward Island, and Quebec, Canada. Findings from this study support the hypothesis that climate worry is associated with psychological distress in Canadian youth. Across all genders, the mean psychological distress score was 18.3 (std. dev. 12.1, p = <0.05) and the mean climate worry score was 9.0 (std. dev. 1.9, p = <0.05). The results of this study show that as scores of climate worry increase, scores of psychological distress also increase (Beta = 0.7, p = <0.05). Gender-stratified models were run to ascertain differences in the experience of climate worry and psychological distress for cis-gendered boys, cis-gendered girls, and gender diverse individuals. Results of this thesis reveal that climate worry is modestly associated with increases in psychological distress and may be used to inform future research on the associations between climate worry and psychological distress. Future studies should aim to explore potential causal pathways for the inception of climate worry (e.g., media literacy and climate worry rooted in media use), and outcomes of climate worry (e.g., psychological distress, anxious, or depressive symptoms).
Governance and Public Engagement from the Perspectives of Antimicrobial Resistance Experts: An Explorative Study
(University of Waterloo, 2025-04-29) Abdelrahman, Sara
Background: Antimicrobial resistance (AMR) has long been a threat to medicine as it reduces the efficacy of antimicrobials that once saved millions of lives. AMR is a multifaceted issue that has many drivers and thus, multiple actors need to be involved for an effective solution. Current prescribing practices, non-compliance issues, and even climate change are accelerating the rate at which AMR is occurring, hence current and future plans need to focus on hindering its propagation. AMR is a One Health problem that involves many sectors and in essence a social issue that necessitates proper governance structures across sectors as well as effective public engagement. Objectives: The main objective of this study was to identify and compare governance and public engagement elements that emerged from Swedish and Malaysian AMR experts’ discussions during two workshops held on September and October 2020 on the effectiveness and sustainability of taxation and Infection Prevention Control measures in tackling AMR in the future. Specifically, the objectives of this study were to: (i) identify and compare governance elements emerging from Sweden and Malaysia, (ii) identify public engagement elements emerging from Sweden and Malaysia, and (iii) identify and compare context-specific governance and public engagement challenges and opportunities in both contexts. Methods: A secondary data analysis was conducted on pre-existing data collected from 18 AMR experts in Sweden and Malaysia that discussed taxation and infection prevention control measures as effective interventions to tackle AMR in 2030 and 2050. These data were analyzed for governance and public engagement elements using Anderson’s governance framework and the sociocognitive theory, respectively. NVivo software was used to analyze and organize the data based on the governance and public engagement frameworks selected; new elements of governance and public engagement that emerged were also added as necessary. Results: Swedish and Malaysian AMR experts discussed all 18 of Anderson's governance elements. Swedish and Malaysian AMR experts described governance as needing proper diagnostics, a One Health surveillance system, investment into research and development, lesson learning, and collaboration across industries and countries. Swedish AMR experts discussed all 6 elements of public engagement, whereas Malaysian experts discussed only four. Malaysian experts did not discuss ‘goals’ and ‘sociocultural facilitators.’ While Swedish AMR experts discussed people’s willingness to pay for antibiotic-free products and needing quick fixes, Malaysian AMR experts discussed the issue of wet markets in Southeast Asia. Context-specific opportunities and challenges differed across the two contexts. Two new elements of governance were identified through Swedish AMR experts’ discussions: incentivization of pharmaceutical companies to develop antimicrobials and raising AMR priority among policymakers. No new elements of governance were revealed through Malaysian experts’ discussions. Consistent messaging was a new element of public engagement revealed through Swedish AMR experts' discussions, while two new elements were revealed through Malaysian AMR experts: AMR message delivery and conflict of interest. Interactions were observed within governance elements, public engagement elements, and between the two frameworks. Conclusion: This study highlighted the multidisciplinary nature of a complex issue like AMR. It is the first to use Anderson’s governance framework to evaluate AMR discussions presented by experts from Sweden and Malaysia and employ the sociocognitive theory, which is often underrepresented in the AMR literature. The discovery of new elements of governance, public engagement, and the overall interactions between the two concepts shows that there is much yet to know about AMR and its driving factors.
Supporting Healthy Aging with Active Assisted Living Technology: From Developing Smart Home Data Ecosystem to Activities of Daily Living Recognition
(University of Waterloo, 2025-04-23) Wang, Kang
Background: The aging population is growing rapidly worldwide, posing significant challenges for healthcare systems. This demographic shift demands innovative approaches to address the unique physical, cognitive, and social needs of older adults.. Traditional healthcare systems are often ill-equipped to provide continuous monitoring and support, leading to increased pressure on caregivers and healthcare providers. Active Assisted Living technologies, combined with Artificial Intelligence, present an opportunity to bridge this gap by integrating advanced sensors and analytics into everyday living environments. These technologies can enhance healthcare monitoring, promote independent living, and improve overall well-being for aging populations. The aim of this thesis is to develop and evaluate AI-enhanced AAL systems that address key challenges in aging healthcare. This includes constructing robust data ecosystems for sensor integration, advancing methods for physical indicator prediction, Activities of Daily Living recognition, and ensuring the adaptability of these technologies for real-world applications. Methods: This thesis employed a multi-phase research methodology, integrating systematic reviews, infrastructure development, and experimental evaluations to advance Active Assisted Living technologies for aging populations. The research began with a comprehensive scoping review to systematically map the landscape of AI applications in AAL technologies. The review followed the PRISMA methodology, with searches conducted across six databases: PubMed, CINAHL, IEEE Xplore, Scopus, ACM Digital Library, and Web of Science. Studies published over the past decade were considered, resulting in 64 eligible papers that were reviewed and analyzed to identify critical gaps. Building on these findings, a cloud-native AAL data ecosystem was developed to facilitate the collection, integration, and management of sensor data from commercially available AAL devices. This ecosystem was structured across four layers: perception, transportation, processing, and application. Leveraging cloud computing technologies, the system ensured scalability, interoperability, and real-time data processing. Advanced data acquisition and management protocols were implemented to address challenges related to reliability, security, and compliance with health data standards. The functionality of the data ecosystem was validated through a heart rate prediction study using contactless monitoring techniques. Forty participants performed 23 predefined daily living activities in a smart home environment equipped with Swidget ambient sensors and Empatica E4 wristbands. Data collected from ambient sensors were analyzed using machine learning models, such as Random Forests, to predict heart rates accurately. Further research investigated Activities of Daily Living recognition using the same data assets. A proof-of-concept study involving younger adults in controlled smart home environments evaluated the effectiveness of contactless ambient sensors. Machine learning models, such as Adaptive Boosting, Decision Trees, and Gaussian Naive Bayes, were employed to classify daily activities, achieving high accuracy. To address the challenge of generalizability for Activities of Daily Living recognition among population, a hybrid transfer learning framework was developed. This framework combined Correlation Alignment and Conditional Adversarial Domain Adaptation techniques to adapt models trained on younger adults for application in older populations. Experiments involving 26 healthy older adults were conducted in semi-controlled environments, focusing on less structured activities to simulate real-world conditions. Results: The scoping review identified critical gaps in the application of AI within AAL technologies, particularly the lack of centralized data ecosystem and real-world experimentation. The developed cloud-native AAL data ecosystem successfully integrated data from multiple commercially available sensors, facilitating seamless data processing and real-time analytics. The heart rate prediction study achieved a high prediction performance with a Mean Absolute Error of 6.023 using the Random Forest model. The ADLs recognition study, conducted with younger adults in controlled settings, demonstrated an overall accuracy of 0.964 using the Adaptive Boosting model, significantly outperforming wearable sensor-based methods and hybrid modes. The hybrid transfer learning framework further addressed the generalizability challenge by adapting models trained on younger adults in controlled settings to older adults in semi-controlled settings. The hybrid adaptive model achieved an accuracy of 0.576 and an F1-score of 0.538, compared to baseline methods, which achieved only 0.098 in accuracy the most. Additionally, incorporating a small amount of target population data in training enhanced the performance, with accuracy increasing by a maximum of 0.344. Conclusion: This thesis makes significant contributions to the advancement of AAL technologies on public health monitoring by addressing foundational gaps in data ecosystem development, health indicators prediction, ADLs recognition, and its transferability to older adults in real-world. The research demonstrates the feasibility of AI-enhanced AAL systems to provide reliable, scalable, and inclusive solutions for healthcare monitoring and activity recognition in aging populations. By developing and validating methodologies for real-world application, this work also highlights the potential of these technologies to support public health initiatives. The integration of AAL systems into public health frameworks could enable proactive monitoring, early detection of health risks, and personalized interventions, ultimately improving population-level health outcomes. This thesis lays the groundwork for empowering older adults to live independently, safely, and with improved quality of life, while also supporting caregivers and healthcare providers with actionable insights.
An epidemiological investigation of physical-mental multimorbidity: Findings from the 2014 Ontario Child Health Study
(University of Waterloo, 2025-04-09) Reaume, Shannon
Children living with chronic physical illnesses such as diabetes and epilepsy, are at increased risk for developing mental illness. The co-occurrence of at least one physical and at least one mental illness, known as multimorbidity, is not surprising as children living with physical illness and their families endure financial and psychosocial challenges, predisposing these children to experience mental health declines. Child multimorbidity is common. Approximately 25% of children live with physical illnesses that require long-term management and as many as 58% of these children are also diagnosed with a mental illness. The effects of multimorbidity are pervasive, burdening children, families, and the health, social and educational systems. Thus, there is a pressing need to address the mental health challenges of children living with physical illness. A proactive, preventive, public health approach requires a comprehensive understanding of child multimorbidity in a Canadian context. Despite the underlying risk of mental illness across various physical illnesses, child mental health research often excludes childhood physical illness as a determinant of mental illness. Of the research that does exist, samples include older adolescents and young adults with chronic physical illness or include high-risk clinical samples. Research using epidemiological samples, inclusive of young children, has not been conducted since the seminal 1983 Ontario Child Health Study. As survivorship of children living with chronic physical illness has substantially increased with these children living well into adulthood, and as the designs and needs of healthcare and mental health care systems have changed since 1983, this research answers calls to the public health concern of child multimorbidity. To address these knowledge gaps, the following dissertation identified which factors influence the association between chronic physical illness and mental illness (any, mood, anxiety, behavioural and neurodevelopmental disorders), including mediating and moderating factors, and examines differences in mental health service contact based on child health status (healthy, physical illness only, mental illness only, and multimorbid). Three distinct studies, with each study examining one of these main dissertation objectives, have been written for publication. These studies made use of data from the 2014 Ontario Child Health Study-a cross-sectional, epidemiological study of 10,802 children aged 4 to 17 years from 6,587 households from across 240 neighbourhoods. 1) Study 1 objectives included: a. Estimating the lifetime prevalence of childhood chronic physical illness and the six-month prevalence of mental illness and multimorbidity in children; b. Quantifying associations between physical illness and mental disorder, including number of illnesses; and c. Examining factors associated with mental disorder, after adjusting for chronic physical illness. 2) Study 2 objectives included: a. Examining moderating effects of child sex, age, health functioning, mental health service contact, and household income on associations between physical and mental illnesses; and b. Exploring the potential mediating effect of family functioning on physical-mental multimorbidity. 3) Study 3 objectives included: a. Estimating the six-month prevalence of health status and types of mental health service contact; b. Quantifying adjusted associations between child health status and type of mental health service contact; and c. Quantifying adjusted associations between child health status and number of different types of mental health service contacts. In a sample of 10,303 children, the first manuscript estimated childhood chronic physical illness to be 27.8%, while 14.8% of children had mental disorder and 5.4% had multimorbidity. Physical illness was not associated with mental disorders. An ordinal regression illustrated children with two physical illnesses, as compared to no physical illnesses, had increased odds for having any, mood, and anxiety disorders. There were no associations found between children with one or three or more physical illnesses and mental disorders. Notably, health functioning demonstrated a dose-response across health status categories, with healthy children having highest scores and multimorbid children having lowest scores. These findings demonstrate the need for targeted and routine mental health screening in youth with two physical illnesses. Preventative mental health interventions should focus on preventing declines in health functioning. The second manuscript used the subsample of index children (n=6,242). Physical illness was associated with increased odds of mood disorder. Health functioning moderated physical-mental illness associations, such that better health functioning in children with physical illness versus without physical illness, had higher odds for any mental illness, anxiety disorder, and attention-deficit hyperactivity disorder. There were no associations found in children with poorer health functioning and physical illness. No other child or household factors moderated associations and family functioning did not mediate physical-mental multimorbidity. These findings suggest physical-mental multimorbidity is nuanced, with differential effects of physical illness on childhood mental illness. Targeted mental health screening is needed for children living with chronic physical illnesses resulting in better health functioning. The third manuscript estimated 21.4% of children had mental health service contact within the last six months. Regardless of child health status, contact was highest in school-based settings. Children with multimorbidity had higher odds for having every type of mental health service contact (any, general medicine, urgent medicine, alternative, school-based, and specialized mental health) than healthy controls. A dose-response was also observed, such that the number of types of mental health service contacts increased from physical illness to mental illness to multimorbidity. These findings support mental health resource allocation for school-based services. Further research is needed to understand barriers and facilitators of mental health service use including integrated health and mental health care for children with multimorbidity. The findings from this dissertation fill critical knowledge gaps in child physical-mental multimorbidity research. Taken together, these findings show health functioning and not just the mere presence of physical illness is important to consider when examining the nuances and impact of physical illness on child mental health. Moreover, findings show mental health-related contact is similar across child health status. Findings also inform policy, intervention, and clinical research directions. From a policy lens, resources should be allocated to school-based mental health services. Universal mental health intervention efforts, regardless of child health status, should focus on preventing overall-health functioning declines. Regular mental health screenings for children living with chronic physical illness should occur, with early intervention efforts aimed at reducing the incidence of multimorbidity. Vigilant and routine screening is needed for children living with two physical illnesses and for children with better health functioning. Future longitudinal research is needed to elucidate mediating factors in physical-mental multimorbidity. Given proper supports within integrated health services, the incidence and impact of child multimorbidity can be reduced and children living with physical illness can have improved mental health outcomes.
Trajectories of Psychopathology and Mental Health Service Use Among Youth with A Physical Illness
(University of Waterloo, 2025-03-04) Dol, Megan; Ferro, Mark
Youth with chronic physical illness (CPI) are at an increased risk of developing co-occurring mental disorders (i.e., multimorbidity). About 40% of youth with CPI receive a mental disorder diagnosis. The relatively high multimorbidity prevalence suggests this is a pressing public health issue—youth with multimorbidity experience greater symptom severity and functional impairment. In addition, multimorbidity negatively impacts psychosocial outcomes, including health-related quality of life, self-esteem, and academic functioning. Although these children experience poorer outcomes and use a greater amount of mental health services, there is limited understanding of how specific trajectories of mental disorder symptoms (i.e., psychopathology) influence service use over time. By examining the course of psychopathology and its association with mental health service use (MHSU), we can identify critical intervention points aiming to improve the effectiveness of care and allocation of resources. In Canada, the financial burden of mental illness is approximately $51 billion annually, including costs arising from healthcare services, lost productivity, and poor quality of life. Compounding on these burdens, there is an acute shortage of youth-specific mental health services in Canada, where up to 70% of youth with mental health concerns do not receive the specialized services they need. Understanding MHSU in youth with CPI may help efficiently use resources, identify unmet needs, improve the timing of interventions, support families in predicting care needs, and inform policies for targeted and integrated services. This dissertation addresses critical gaps in research on youth psychopathology among you with CPI. While previous studies have explored youth MHSU, few have examined the unique trajectories of psychopathology in this population or how these trajectories affect mental health service use over time. Additionally, limited research has investigated the interplay between parent psychological distress, youth psychopathology, and healthcare use, particularly using longitudinal models. Focusing on these areas, this dissertation provides insights into the complex needs of youth with CPI. It highlights opportunities for improving integrated mental health and healthcare support for this at-risk group. To address these gaps, this dissertation examined youth psychopathology trajectories and transitions and whether psychopathology trajectories impact the association between family factors and MHSU. Specifically, the objectives were to: 1) identify distinct trajectories of psychopathology among youth with a CPI; 2) validate these trajectories by comparing with categorical classifications produced by a diagnostic interview tool; 3) examine predictors of the trajectory groups; 4) identify distinct subgroups of youth psychopathology; 5) examine transitions across these subgroups of psychopathology; 6) identify predictors of such transitions; 7) explore if youth psychopathology trajectories mediate the association between family factors and MHSU. The first study developed a trajectory model using latent class growth analysis (LCGA) to examine the optimal number of trajectories of youth psychopathology and predictors of the different trajectories. Results indicated a three-trajectory model characterized as low-stable, moderate-decreasing, and high-decreasing trajectories. Older age, higher disability, greater parent psychological distress, and higher household income were associated with less favourable trajectories. Results demonstrate that youth with CPI exhibit different courses of psychopathology, and that different individual and family characteristics are associated with trajectory group membership. The second study used latent profile analysis to identify four profiles of youth psychopathology: low psychopathology, primarily internalizing, primarily externalizing, and high psychopathology. Additionally, latent transition analysis was used to track transitions between these profiles over time. Many youths in the primarily internalizing subgroup transitioned to the low psychopathology subgroup over time. Further, youth classified in the high psychopathology subgroup from six to 24 months were more likely to have persistent psychopathology. These findings suggest that youth with CPI exhibit distinct profiles of psychopathology, with unique symptom combinations and patterns of change over time, emphasizing the potential for different mental health needs and trajectories within this population. Youth with CPI do not all experience psychopathology in the same way, and they may shift between profiles, suggesting dynamic changes in symptom patterns. The third study conducted a path analysis to determine if youth psychopathology trajectories mediate the association between family factors (parent psychological distress and family functioning) and MHSU (i.e., contact with a healthcare professional). Results demonstrated that youth psychopathology trajectories (subclinical vs. low) mediate the association between parent psychological distress and contact with a healthcare professional. These findings support using a family-centred care approach to youth healthcare to minimize the burden on families and promote well-being and positive health outcomes. This dissertation fills a critical gap in terms of knowledge of psychopathology and MHSU among youth with CPI. Taken together, these findings can be distilled into four themes: (1) call for integrated physical and mental healthcare; (2) early identification of psychopathology among youth with CPI; (3) adaptive treatment approaches to care; and (4) the need for family-centred care in youth mental health settings. Future longitudinal research should investigate transitions across psychopathology profiles over longer periods and investigate other potential mediators that facilitate or impede the use of mental health services for youth with CPI.
Evaluating the impact of participation in school-based physical education lessons on adolescent health and wellbeing in Ontario: Findings from the COMPASS study
(University of Waterloo, 2025-01-30) Buchan, Marisa Claire; Leatherdale, Scott
Physical activity rates among adolescents in Canada are critically low; only about one in every three grade 9 students are meeting the recommended 60 minutes per day of moderate to vigorous physical activity (MVPA). These high rates of physical inactivity among youth are alarming, as physical activity is essential for both physical and mental wellbeing, and it sets the foundation for healthy habits in adulthood. School-based physical activities including physical education (PE) classes, and intramural and varsity sport programs are ideally situated for the promotion of physical activity as they can reach a large number of youth and overcome many of the barriers associated with extracurricular activities. PE is designed to provide opportunity for youth of all ages to engage in physical activity that is structured into their weekly routine. However, in secondary school, a period that is critical for establishing healthy behaviour patterns for later in life, PE becomes non-mandatory for students in many provinces and territories across Canada, resulting in a missed opportunity to engage adolescents in regular physical activity. Ontario currently has the most lenient PE policy in Canada, with students only required to complete one secondary school-level PE course. To date, only four studies have examined the impact of PE programming in Canada on physical activity levels, only one of which included students from the province of Ontario. No published studies to date have explored the impact of PE participation on mental health outcomes among adolescents in Canada. The lack of evidence in this domain renders it challenging to determine the effectiveness of PE or make recommendations to enhance PE programs to maximize their impact on student health and wellbeing. This dissertation aimed to provide a deeper understanding of the patterns of physical activity behaviours and the impacts of participating in non-mandatory secondary school PE on physical activity and mental health outcomes among adolescents in Ontario. Specifically, Study 1 characterized longitudinal physical activity profiles of non-mandatory PE participation, adherence to physical activity guidelines, and sport participation throughout secondary school. Study 2 quantified the impact of participation in PE on physical activity levels, over time. Study 3 quantified the impact of PE participation on student mental health, over time. This dissertation utilized linked longitudinal data from students in Ontario who participated in four consecutive years of the COMPASS Study (Time 1: 2015-16; Time 2: 2016-17; Time 3: 2017-18; Time 4: 2018-19). The COMPASS Study is a school-based prospective cohort study (2012-2027) that collects demographic, behavioural, and mental health data from students annually across Canada. Study 1 utilized a repeated measures latent class analysis to identify longitudinal physical activity profiles of adolescents in Ontario. Studies 2 and 3 utilized linear mixed models to estimate the average effect of PE participation on (a) minutes of MVPA (Study 2) and (b) symptoms of anxiety, (c) symptoms of depression, and (d) psychological wellbeing (Study 3), over time. Models in Studies 2 and 3 were adjusted using doubly robust propensity score methodology to account for self-selection biases that may influence PE participation. Findings from Study 1 illustrated that there are distinct, clustered physical activity profiles among adolescents which vary by sex; three physical activity profiles were identified among both female and male students: Guidelines, PE & Sports, and Guidelines & Sports. A fourth profile was identified among male students only: Inactive. Study 2 demonstrated that participation in secondary school PE had a significant positive impact on MVPA levels over time, and effects were most pronounced for male students and during the semester of PE participation. Study 2 also illustrated that the benefits of PE remained present in the semester opposite to PE participation, suggesting that the benefits of PE extended beyond the MVPA accumulated during class-time. In Study 3, PE participation was not associated with symptoms of anxiety or depression, over time. Study 3 also found that male students enrolled (but not currently participating) in PE were found to have higher psychological wellbeing compared to those not enrolled in PE within the academic year. This dissertation fills an important gap with respect to our understanding of PE programming in Ontario secondary schools. Findings from this dissertation revealed that many students are choosing not to enroll in PE, with a particularly high-risk subgroup of male adolescents showing low participation across several physical activity behaviours during secondary school. Among male students who elect to participate, PE was found to positively impact time spent in MVPA and psychological wellbeing. These results highlight the potential of PE for improving the health and wellbeing of adolescents, although low participation rates limit these benefits being experienced at the population-level. Importantly, all three studies identified sex-based differences in the physical activity profiles and the impact of PE on health outcomes; female students were found to have lower PE participation rates and experienced reduced benefits compared to male students. These result underscore the importance of promoting inclusive environments in PE to ensure health benefits are experienced by all adolescents, regardless of sex and other key characteristics. Findings from this dissertation offer valuable insights for public health programming, particularly within the school context; decision-makers in Canada should explore ways to increase PE participation across secondary schools, paying particular attention to female students and those not participating in other forms of physical activity.
Exploring the Wellbeing and Food Security of Ethical Vegans through the Human and More-than-Human World
(University of Waterloo, 2025-01-27) Russell, Julia; Skinner, Kelly
Background: Health and environmental data reveal significant challenges faced by populations around the word in relationship to food. Complex choices and constraints shape people’s dietary patterns. While there is often debate about which eating patterns people should follow, for vegans ethical motivations are paramount. Vegan diets can be healthy diets, but there remains a gap in the literature surrounding veganism and overall wellbeing, including food security and connection to nature. Objectives: Taking into consideration both human and more-than-human factors this research explored how vegans live their lives embedded within the complex circumstances that shape their wellbeing. This exploration was informed by the application of a holistic model of health (the Revised Mandala of Health) and the use of an ecofeminist lens. Through a series of three studies and one methodological reflection, this research addressed the following objectives: (1) To investigate how ethical veganism influences a person’s experience and conceptualization of food security; (2) To explore the success and challenges faced by ethical vegans, how they may resist these challenges, and the implications for wellbeing; and (3) To explore ethical vegans’ experiences with the more-than-human world, and the implications for their wellbeing and coping strategies. Methods: The first study (Chapter 2) used focus groups to learn about vegans’ experiences and ideas related to food security at the individual, household and community levels. Four focus groups were held, of which three were comprised of vegans who in the year prior had experienced food security, with the final focus group being reserved for vegans who had experienced food insecurity. The focus groups’ data were analysed using Tracy’s phronetic iterative analysis approach. The second study (Chapter 3) used semi-structured interviews to collect data on veganism and wellbeing from 26 participants. The data from these semi-structured interviews were analysed using reflexive thematic analysis (RTA). The third study (Chapter 4) had six participants who took part in both a 2-day, group, body-map storytelling (BMST) workshop and then a follow-up individual, semi-structured interview. Data collected over the course of the body-map storytelling workshop included each participant’s presentation of their body-map to the group, as well as a written ‘testimonio’, two end of day reflective exercises, and one focus group. All data from this third study were analysed together using RTA. Finally, a fourth component was generated for this dissertation (Chapter 5). This methodological reflection was written based on the lead researcher’s impressions of the BMST workshop and comments about this workshop that were shared by the participants during data collection for the third study. Results: The results of Study 1 indicated that responsibility was a prominent feeling experienced by the participants both in relationship to their veganism and their experiences of food (in)security. The participants believed they should be informed about the food system, know how to shop frugally, and have cooking skills. Feelings of personal responsibility for food security may have been amplified by the perception of the absence of a vegan-friendly social safety net. The participants noted vegan foods could be nutritious, convenient, and inexpensive but not generally all these things at once. Therefore, compromising on at least one feature of their food was often needed. Participants in both the food secure and food insecure groups explained how at times they experienced difficulty accessing vegan-friendly foods. The results of Study 2 demonstrated that veganism is regarded as a positive way of living that though challenging at times, especially early on in one’s experience and in relation to social relationships, was of overall net benefit to the vegan participants. This benefit contributed to enhanced wellbeing. The areas of wellbeing the participants identified most often as being influenced by veganism were the mental and emotional realms. The participants’ identities influenced their experiences of veganism. In navigating life as vegans the participants eschewed the belief in a ‘perfect’ veganism, which may have contributed to the longevity of their veganism. The results of Study 3 showed the participants were ecologically embedded. Being ecologically embedded meant that when the participants perceived harm to the more-than-human world they subsequently felt a negative effect on their own wellbeing, including as solastalgia. However, being ecologically embedded also meant that participants experienced enhanced wellbeing through their connection to the more-than-human world. In the methodological reflection, the researchers argue that while BMST requires significant participant involvement it can be a rewarding approach for both participants and researchers, and a safe method of data collection if careful attention is paid to the social location of potential participants and the sensitivity of the research topic. The researchers found different data collection approaches were more and less effective during the BMST workshop and they offer practical considerations for the design and undertaking of future BMST workshops. Conclusions: Through the completion of three studies and one methodological reflection this research found that veganism was a positive force that enhanced wellbeing in the lives of the participants. As veganism is outside of the norm in Western cultures, being vegan did lead to challenges for the participants, but the challenges were not with veganism itself, rather the challenges lay in the social ramifications and accessibility of foods suitable for vegans. Participants felt the benefits of veganism outweighed the challenges. Considering the results via their alignment with the Revised Mandala of Health suggests that veganism can have health promoting properties for vegans and the more-than-human world. As plant-based diets are increasingly considered a way to address issues of health and sustainability, this study adds important understandings about the personal value and maintenance of veganism.
Impacts of Alternative Policing on Officer Health: The Community Engagement Unit (CEU)
(University of Waterloo, 2025-01-21) Fenton, Arden; Mielke, John; Anthony, Kelly
Created by the Waterloo Regional Police Service (Ontario-Canada), the Community Engagement Unit (CEU) links high-needs community members with specially trained police and to appropriate social services. Whether living with homelessness, poor mental health, domestic violence, or substance use, and often with several of these challenges simultaneously, high-needs community members often require greater police attention. Indeed, CEU officers act as a “911 calls diversion centre” by redirecting high-needs individuals away from traditional law enforcement approaches and towards relevant social service agencies. However, due to their unique work environment, CEU officers likely experience additional/unique stressors that may impact their health. As a result, when developing alternative policing units like the CEU, recognizing the potential stressors of such work and their impact on the police service is essential. This mixed methods study utilizes semi-structured interviews and surveys to assess the work environment of CEU officers relative to traditional police officers to improve our understanding of stress-related health risk factors within alternative policing units. Five CEU officers were recruited via email to participate in a 1-hour semi-structured interview. Thematic analysis of semi-structured interviews developed the CEU ‘phenotype’ by assessing the unique work environment, roles, and responsibilities of CEU officers. The CEU officers were asked to reflect on these aspects of their work compared to previous units (primarily patrol). The experience of stress in CEU is more prolonged and chronic, given the continuous nature of their interactions with high-needs individuals, as opposed to the fast-paced, case-to-case stress nature of patrol units. This ‘slow-burn’ stress, combined with the frustration of navigating under-resourced community social support systems and moral distress when cases lack resolution, is likely to present unique challenges to the officers' health and well-being. Surveys collected standard demographic information and included validated scales to measure self-reported health, health-risk behaviours, given and received social support, and varying levels and types of police-specific stressors using the operational and organizational police stress questionnaires (PSQ-Op, PSQ-Org). Seven CEU officers (14.0%) and 43 traditional (TRAD) officers (86.0%) were recruited via e-mail to participate in the survey. CEU officers had lower levels of fatigue (-42.5%), shiftwork (-57.6%), working alone at night (-58.3%) and internal investigations (-63.3%) compared to TRAD officers. This study reveals distinct differences between CEU and TRAD officers. CEU officers report lower fatigue and less shiftwork but experience prolonged "slow-burn" stress due to ongoing interactions with high-needs individuals and frustrations with under-resourced support systems. These findings emphasize the need for tailored support systems in alternative policing units like the CEU. Improved mental health resources, decompression opportunities, and clear mandates can help reduce health risks associated with their unique stressors. This study adds to the research on alternative policing, highlighting the importance of understanding occupational health in non-traditional police roles.
Understanding the Individual and Combined Impacts of Social Isolation and Loneliness on Memory: A Sequential Explanatory Mixed Methods Study
(University of Waterloo, 2025-01-14) Kang, Ji Won; Oremus, Mark
Social isolation (SI) and loneliness (LON) are important risk factors for cognitive health; however, their combined effects on memory, a key cognitive domain, are under-researched. This thesis is the first sequential, explanatory, mixed methods study to examine how SI and LON individually and together affect memory in middle-aged and older adults. Using three waves of data from the Canadian Longitudinal Study on Aging (CLSA), spread over six years, LON was measured by the loneliness frequency question from the 10-item Center for Epidemiologic Studies Depression Scale. SI was measured by an index based on marital/cohabiting status, retirement status, social activity participation, and number/frequency of social network contacts. Memory was evaluated with combined immediate- and delayed-recall z-scores from the Rey Auditory Verbal Learning Test. Primary analyses utilized all available data across the three waves of CLSA data and retained participants with missing covariate data (n = 14,208). Linear mixed models to account for all three waves of data were used to regress combined memory scores onto SI and LON, adjusting for sociodemographic, health, functional ability, and lifestyle variables. Results showed that combined SI and LON had the greatest negative impact on memory (least-squares mean: -0.80 [95% confidence-interval: -1.22, -0.39]), followed by LON alone (-0.73 [-1.13, -0.34]), then SI alone (-0.69 [1.09, -0.29]), and lastly by experiencing neither (-0.65 [-1.05, -0.25]). Two sensitivity analyses – one excluding participants with missing covariate data from the primary analysis sample and another employing a multiple imputation approach – both confirmed these findings. The qualitative phase involved phenomenological, semi-structured interviews with ten individuals – recruited through purposive and snowball sampling – to explain the quantitative results from the perspective of middle-aged and older adults. Based on thematic analysis, qualitative participants believed that LON has a stronger negative impact on memory than SI because individuals can still engage in mental stimulation while isolated, but are less motivated to do so when feeling lonely. Participants also believed that the combination of SI and LON is most detrimental to memory, as these conditions can exacerbate each other in a feedback loop, leading those who experience both to be more prone to self-destructive behaviours. This research highlights the need for targeted interventions involving multimodal brain health programs, which simultaneously address multiple risk factors for cognitive decline – such as SI and LON – through actionable steps, including staying socially connected, finding meaning in life, engaging in cognitively stimulating physical/leisure activities, managing medical conditions, and adopting healthy lifestyle choices.
Perceived Differential Parenting and Childhood Physical-Mental Multimorbidity
(University of Waterloo, 2025-01-02) Barclay, Christopher; Ferro, Mark
Background: Physical-mental multimorbidity (herein multimorbidity), the co-occurrence of a chronic physical and mental illness, affects a substantial proportion of children, compromising their quality of life, causing hardship for families, and burdening the healthcare system. Research investigating the potential causal mechanisms of childhood multimorbidity is scarce. Child-perceived differences in parenting style within families (i.e., differential parenting) may be one of these mechanisms. Objectives: 1— What is the direction and strength of the association between perceived differential parenting and psychopathology in children with chronic physical illnesses (i.e., multimorbidity)? 2— Do birth order and concordant/discordant child-sibling sex pairs moderate this association? 3— Does child self-concept mediate this association? Methods: Data come from the Multimorbidity in Children and Youth across the Life-course (MY LIFE) study. Perceived differential parenting was assessed using the Sibling Inventory of Differential Experiences (SIDE), and child psychopathology was assessed using the Emotional Behavioural Scale (EBS). linear mixed models were used to determine the directionality and strength of the association between perceived differential parenting and multimorbidity. Stratified models were computed to determine the moderating effect of birth order and child-sibling sex pairs. The product of coefficients approach was used alongside generalized linear modelling to determine the mediating effect of child self-concept. Implications: Health professionals can utilize findings to foster better communication within families and refer those at-risk to appropriate resources. Findings can also inform the integration of physical and mental health services to promote healthy child self-concept and nurturing family environments to reduce the incidence of childhood multimorbidity.
Facing the Heat: Utilizing the Internet of Things (IoT) to Enhance Preparedness Against Extreme Heat Events in Canadian Households
(University of Waterloo, 2025-01-02) Oetomo, Arlene; Morita, Plinio P.
Background: Heat waves pose a severe and growing health risk in Canada, with an estimated 17 million people likely to experience extreme heat in the coming decades. These risks are heightened in urban areas, where the urban heat island effect exacerbates dangerous temperatures. Extreme heat events are increasingly frequent, intense, and widespread, with record-breaking heat waves affecting almost every region globally. Despite increasing awareness, many of the dangers associated with extreme heat are only now being fully realized. This work addresses data gaps related to indoor heat vulnerability needed to create safe indoor conditions. Education and early warnings are critical to protecting the population, especially vulnerable groups. Extreme heat is a climate justice issue, disproportionately affecting marginalized groups with fewer resources to cope. Methods: This study used smart thermostats (ecobee) to collect real-time indoor temperature data, developing a hyperlocal alert system for indoor heat risks. First, we analyzed ecobee's "Donate Your Data" dataset to identify homes without air conditioning and to explore indoor and outdoor temperature differences during the 2018 Quebec heat wave. Next, a scoping review assessed the use of IoT or similar devices, focusing on climate-related impacts. Canadians were surveyed through Google Opinion Rewards to evaluate their understanding of heat waves and preferences for receiving heat-related information. Online discourse about heat waves was analyzed using Latent Dirichlet Allocation (LDA) topic modelling on tweets from Twitter (now X), via natural language processing (NLP), and manually using an inductive approach to observe emerging narratives and themes. Finally, in the summer of 2022, a full-scale deployment of smart thermostats was conducted in community housing without air conditioning in collaboration with housing and public health organizations. Indoor temperature data was collected from 70 British Columbia and Ottawa homes, with results shared via daily emails and an elastic dashboard. Three surveys captured details on building types, resident behaviours, and heat-related habits. Results: The scoping review found that using IoT and low-cost sensors for indoor heat monitoring is an emerging field that could strengthen early warning systems and heat response efforts. The survey results showed that most Canadians preferred to receive heat wave information online, with income correlating to the usage of mobile devices. Older demographics still preferred traditional media like TV, radio, and newspapers. Online discussions centred around activities, personal experiences, advice, and warnings related to heat waves. Emerging trends of climate denial were present in both survey and tweet samples. Indoor temperature data revealed that homes frequently exceeded emerging threshold recommendations of 26°C and 31°C, with some homes recording temperatures as high as 38°C on non-heat wave days. Participants in British Columbia were better prepared and had higher heat safety awareness than other regions. This is the first Canadian study to explore the use of IoT smart thermostats in near-real-time indoor temperature monitoring to protect vulnerable populations from extreme heat. Significant differences were observed between indoor and outdoor temperatures (P <0.001). Discussion and Conclusion: This work shows the potential of IoT devices and social media to improve real-time monitoring and inform evidence-based public health interventions for extreme heat. The widespread adoption of smart thermostats in Canadian homes and the prevalence of social media provide valuable opportunities to address existing data and knowledge gaps. However, the persistence of climate misinformation and denial challenges public health communication efforts. Indoor heat is a public health and equity issue related to poverty, substandard housing, urban planning, and energy access. These interconnected issues must be considered in policy frameworks to protect vulnerable populations. Low-cost sensors and solutions, such as natural ventilation mobile alerts, could support the response to heat health by addressing a data gap. Rapidly analyzing these areas is important as digital spaces evolve to support public health communication. Policymakers must take immediate action to prevent unsafe indoor conditions and protect marginalized communities from the growing threat of extreme heat.
A Community-Based Exploration on the Impacts of Land-Based Learning in an Urban Indigenous Community
(University of Waterloo, 2024-12-20) Bui, Danica; Neufeld, Hannah
Background Connection to the Land is essential for Indigenous Peoples’ health and well-being. Indigenous Food Sovereignty works towards regaining control over traditional food systems. There is a need for sustainable, Indigenous-specific, and accessible urban community Land-based practices. Done in partnership with White Owl Native Ancestry Association (WONAA) and the Wisahkotewinowak Collective (WC), four seasonal Land-based learning events were held. Each event involved a workshop, meal, and gathering at the University of Waterloo’s North Campus Community Gardens. Aims Guided by the interests of project partners, WONAA and WC, the overall purpose of this thesis is to explore and evaluate the impacts of Land-based learning on the local Indigenous and university communities and the PEG project’s effectiveness in establishing networks to facilitate ongoing research and learning to establish a permanent Land-based learning space on campus. The overarching research questions that guided the research are: 1. What are participants’ and facilitators’ perceptions of the Land-based engagement process? 2. What is the effectiveness of Land-based workshops in identifying and prioritizing collaborative Land-based opportunities for learning and research? 3. To what extent can the seasonal workshops establish a local network to facilitate ongoing research and learning in support of the development of an urban Indigenous Land-based learning space on the UW campus? Methods Appreciative Inquiry and Community-Based Participatory Research approaches were used for this thesis. Following each of the events, participants and project collaborators were recruited to participate in interviews. The data for this evaluation was collected through 17 semi-structured interviews with project collaborators and community partners (n=6), urban Indigenous community members (n=6), Indigenous youth and students (n=2), and UW staff (n=3), two focus groups with WONAA and WC staff members (n=5) that were involved with the workshops, and a document review. Reflexive thematic analysis was completed using NVivo for the interview and focus group transcripts, and the documents were analyzed to determine if the budget and timelines were met. Results Overall, participants, collaborators, and facilitators of the Land-based learning events had positive perspectives of establishing a Land-based learning space on campus. The three key themes from the interviews about the Land-based learning events and their potential for building connections to establish a permanent Land-based learning space include: (1) participants’ growing support of Land-based learning (2) creating connections and building relationships and (3) institutional support and project sustainability to support of the development of a permanent urban Indigenous Land-based learning space. The findings from the outcome evaluation, including the interviews, focus group, and documents reflect these themes and include (1) workshop feedback (2) project partners' goals, and (3) identifying opportunities to move forward. These findings show that the community, including project partners, participants, and collaborators, found the Land-based learning events to be a welcoming and positive experience that should become integrated into university curricula to support the university and local community. Conclusion Participants enjoyed the Land-based learning events and supported the establishment of a permanent Land-based learning space at the North Campus Community Gardens. Attending the events and being involved in the project generated ideas for learning and research opportunities, with many participants sharing future workshop ideas and identifying ways to integrate Land-based curricula and research opportunities. The events also connected the local urban- Indigenous community to the university community and helped to strengthen pre-existing relationships between the attendees. Through these connections, the desire for the North Campus Community Garden to become a space for Indigenous learning, teaching, and research, strengthened. Overall, the interview and focus group participants had positive perspectives of the events and the establishment of a permanent Land-based learning space at the North Campus Community Gardens, shared that Land-based learning was a need in the urban Indigenous and university community, and emphasized that further support from UW, longer-term funding, and physical and social infrastructure was needed for the project’s sustainability.
Developing Quality Indicators for Home-based Teleconsultation in Secondary Stroke Prevention
(University of Waterloo, 2024-12-02) Meng, Guangxia; Chen, Helen; McAiney, Carrie
home-based teleconsultation service quality patient satisfaction quality indicators secondary stroke prevention
A psychometric evaluation and application of a measure of food literacy among young adults
(University of Waterloo, 2024-11-11) Holmes, Martin; Kirkpatrick, Sharon
Background: Food literacy is an emerging study area encompassing the knowledge, skills, and attitudes required to navigate dynamic food systems. Food literacy has been suggested as a potential leverage point for improving diet quality and health outcomes. The emerging adult population, facing unique dietary and life transitions, is highlighted as an important group in public health research. Following calls for standard and well-evaluated measures of food literacy, a collaborative working group of public health nutrition practitioners in Ontario, Canada, led the development of a comprehensive food literacy measure, the FLit50, for use with young adults. To support the broad use of the measure in public health practice, assessment of the construct validity of the FLit50 and the development of a shortened version were desired by the public health nutrition practitioners. Objectives: The objectives of this dissertation were to: (1) evaluate the construct validity of the FLit50 measure among post-secondary students (Chapter 5); (2) analyze the characteristics of the FLit50 items to facilitate the development and evaluation of a shortened measure (Chapter 6); and (3) explore the demographic, income adequacy, studentship, and health correlates of food literacy among post-secondary students (Chapter 7). This work was undertaken in collaboration with the public health nutrition practitioners. Methods and results: The first study (Chapter 5) drew upon data from 457 post-secondary students in Ontario, Canada, to evaluate the measure's construct validity by assessing whether it could differentiate between groups hypothesized to have differences in food literacy. The FLit50 showed adequate construct validity, evidenced by higher median food literacy scores among students in food and nutrition programs (KW χ2) = 108, p < 0.001), women (KW χ2= 49.2, p < 0.001), those with adequate health literacy (KW χ2 = 20.6, p < 0.001), those with higher general health (KW χ2 = 49.5, p < 0.001), those with higher mental health (KW χ2 = 17.4, p < 0.001), and those experiencing food security in the past 12 months (KW χ2 = 21.9, p < 0.001), as hypothesized. No differences were observed by age (KW χ2 = 5.24, p = 0.63) or perceived income adequacy (KW χ2 = 4.21, p = 0.38). Differences in group means were observed as hypothesized for scores on items reflecting the underlying domains of food and nutrition knowledge and self-efficacy and confidence, but not food skills or ecological factors. The second study (Chapter 6) involved the application of the 2-parameter Item Response Theory, using data from postsecondary students (n=457) along with data collected from young adults across Canada during the initial development of the measure (n=351). Item difficulty (mean= -1.72 SD from the sample’s average food literacy ability level, range: -3.64 to 3.05 SD) and item discrimination (mean= 1.78, range: 0.33 to 8.43) characteristics were estimated for items on the FLit50. The parameters informed discussions with the public health nutrition practitioner partners to select sixteen items for inclusion in the shortened measure, the FLit16. The correlation coefficient between scores on the FLit50 and the FLit16 was estimated, and whether the FLit16 could differentiate among groups hypothesized to have different levels of food literacy, as per study 1, was examined. Scores from the two versions of the measure were strongly and positively correlated (Rho = 0.87, p < 0.01) and the short measure was able to differentiate among groups, consistent with the full measure. The third study (Chapter 7) drew upon data from the sample of postsecondary students to explore associations between demographic, income, studentship, and health characteristics, identified a priori based on the emerging food literacy literature, and food literacy scores using multiple linear regression analysis. Data from 413 students were included in these analyses after accounting for missing data on the characteristics of interest. Food literacy was assessed using the FLit50 measure, with a mean score of 42 of 49 points. Adjusting for other characteristics, food literacy was higher among women compared to men (β = 2.509, p < 0.001) and those who reported positive or neutral general health (β = 1.743, p < 0.001). Food literacy was lower among individuals identifying as East/Southeast Asian (β = -2.036, p < 0.001), South Asian (β = -2.409, p < 0.001), and other racial/ethnic identities (β = -1.568, p = 0.005) compared to those identifying as White. Food literacy was also lower among those who lived on-campus (β = -1.457, p = 0.073) and those experiencing food insecurity (β = -1.274, p = 0.004). Food literacy scores did not differ by age, income adequacy, domestic or international studentship, whether students attended college or university, household composition, or self-reported mental health status. The regression analysis yielded an R2 of 0.403, indicating that 40% of the variance in food literacy scores was explained by this model, with an overall significance of F(15, 396 DF) = 17.79, p < 0.001. Conclusions: This dissertation continues the work of the collaboration of public health nutritionists by furthering two of its main aims: establishing the construct validity of the FLit50 and developing a shortened measure that demonstrates construct validity. The availability of two well-evaluated measures presents opportunities to better understand and monitor food literacy in emerging adults and assess associations with factors such as diet quality.
Does social rank influence AMPA receptor subunits in the medial prefrontal cortex of adult male and female rats?
(University of Waterloo, 2024-10-21) Solomon, Eden; Mielke, John
Social dominance hierarchies are ubiquitously observed in social species across the animal kingdom. Social interactions, including resource competition and conflict, shape dominance structures, where animals are ranked as dominant, or subordinate to one another. Previous work has implicated the medial prefrontal cortex (mPFC) as a key brain region responsible for controlling social hierarchy through α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPA) function. The trafficking of AMPARs at the synapse plays a key role in synaptic plasticity, and is mediated by interactions between AMPARs and their associated auxiliary proteins. To date, no studies have explored the expression of AMPAR subunits and their auxiliary proteins in the context of a social hierarchy. As a result, the current study aimed to elucidate the effect that social rank might have on the most abundant AMPAR subunits, GluA1 and GluA2, along with their principal auxiliary proteins, GRIP1, PICK1, and stargazin, in both male and female rats.
Machine Learning Approach and Adolescent Health Implementation of Machine Learning Algorithms to Explore Adolescent Health, BMI and Weight Perception Using COMPASS Study
(University of Waterloo, 2024-09-24) Zhang, Qianyu; Leatherdale, Scott; Chen, Helen
Abstract Introduction Adolescence is critical for behaviour formation and physical, social, and psychological changes. The risk related to unhealthy behaviours occurring during this stage can emerge in early adulthood and could lead to adverse outcomes. The COVID-19 pandemic has significantly impacted the youth’s characteristics and the school’s learning environment. Exploring the profile of Canadian youth before and after COVID-19 helps understand the factors that influence student engagement in the multi-domain setting, including school activities, mental health, healthy eating, etc. Among the various aspects of student profile, childhood obesity and weight perceptions are two important topics for Canadian youth's health and well-being. Obesity in children is a complex public health concern in Canada. Almost 1 in 7 children are considered obese, and 75% of obese children are obese in their adulthood when they grow up. Additionally, a youth’s perception of their weight is often connected to their BMI status. Studies have shown that adolescents who are overweight and obese tend to underestimate their true weight, and the ones with normal weight could overestimate their weight status. Both overweight and obese or misperception of body weight are risk factors for developing non-communicable diseases in adulthood and can lead to worse mental health issues, such as lower self-esteem. Therefore, observing these two aspects and related impactful factors is necessary for informing youth obesity preventive intervention. Compared to traditional statistics, machine learning has proven effective in handling the complex relationships between multidomain variables and in detecting nonlinear relationships between the predictor variables and the target outcome. This thesis explores behavioural patterns, specifically BMI and weight perception, among the Canadian youth participating in the COMPASS study. Objective and Methods The dissertation utilized Wave 7 (2018-19) and Wave 9 (2020-21), and linked data from Wave 9 to 11 (2020-23) of the COMPASS study. This ongoing survey-based cohort study includes grade 9-12 students attending secondary schools in Alberta, British Columbia, Ontario, and Quebec in Canada. The survey questions cover multiple aspects of student health behaviours, including eating, sedentary behaviour, alcohol, tobacco, and marijuana use, bullying, academic performance, physical activity, BMI, and school connectedness. Study 1 applied k-means clustering analysis to establish student behaviour profiles, followed by a Random Forest model (RF) to identify the factors associated with the characteristics before and after COVID-19. Among the various student-level behaviour factors, Study 2 focused on self-reported BMI by predicting youth BMI status and identified associated factors using six supervised machine learning classifiers, K-Nearest Neighbour, Logistic Regression, Support Vector Machine, Random Forest, Multinomial Naïve Bayes, and Extreme Gradient Boosting (XGBoost) between Complete Case Analysis (CCA) and multiple imputation (MI) approaches. Since weight perception was identified as the most significant factor associated with BMI prediction in Study 2, Study 3 used weight perception as the outcome variable. This study explored the transition pattern of student weight perception and the associated factors through the Markov Chain, Multinomial Logistic Regression, and time-series deep learning models, including Recurrent Neural Networks (RNN) and Long Short-Term Memory (LSTM). The Shapley Additive Explanations (SHAP) analysis was applied for all three studies to assess the model interpretability. Results Study 1 found that in both pre-COVID (2018-19) and post-COVID (2020-21) cohorts, clusters were distinguished as closely involved with substance use and lower psychological well-being, including personal relationships with their families or unwillingness to discuss their mental health with an adult at school. However, the number of students in these clusters was relatively low compared to the other clusters, comprising only 0.5% of the pre-COVID cohort and 0.2% of the post-COVID cohort. In sub-clusters from the pre-COVID cohort that excluded substance use factors, students who skipped more than 20 classes, did not complete homework, and were involved in bullying were more likely to be grouped together in one sub-cluster compared to students without these behaviours. Additionally, those intending to lose weight, perceiving themselves as overweight,and being less active had higher odds of being in one sub-cluster compared to those without weight change intentions and who perceived their weight as about the right. In the sub-clusters of the post-COVID cohort, students with adverse mental health well-being, higher anxiety scores, self-reported overweight or obese BMI, and those failing to meet the guidelines of at least 60 minutes of physical activity per day were more likely to be grouped together in one sub-cluster compared to the students with the opposite behaviours. Moreover, students with increased cannabis use, less physical activity, lower flourishing scores and higher anxiety scores were more likely to be in one group relative to students who reported no change in cannabis use. Study 2 discovered that, among both CCA and MI approaches, XGBoost achieved the best performance in predicting BMI compared to those using Support Vector Machine (SVM) and Random Forest (RF). In CCA, it achieved an overall accuracy and ROC-AUC value of 0.64 and 0.78. The model performance was similar in MI and yielded an overall accuracy of 0.64 and ROC-AUC value of 0.79. Based on the SHAP summary plot, the most important predictors were weight perception, gender, and weight change intention in all three BMI classes, and the result was consistent in both CCA and MI. According to the SHAP summary plot, the most significant predictors in all three BMI classes were further explained by weight perception, gender and weight change intention. Students who perceived themselves as slightly or very overweight and were trying to lose weight were classified into the overweight and obese class, while model prediction on health weight BMI involved perceiving the right weight and not trying to change their weight. Additionally, gender was emerged as the most significant variable in the unknown BMI class, with model predicting that females and gender minorities were more likely to be categorized in the unknown weight class compared to male students. Study 3 used the MI approaches on the linked dataset. It found that although there was a moderate probability of transitioning from underweight or overweight to about the right weight and a minor probability of changing from underweight to overweight, most youths were more likely to stay in the same weight perception as the previous year. In addition, Study 3 identified predictors associated with weight perception transition over time. Students with underweight BMI, the intention of gaining weight and disagreement with discussing their problems with families in Year 1 had a higher likelihood of perceiving themselves as underweight in Year 2. While overweight and obese or unknown BMI students who had the intention of losing weight and decreased time on social media after COVID-19 in Year 1 were more likely to have an overweight perception in Year 2. Compared to peers who stayed at perceiving about the right weight in Year 2, underweight BMI students had higher odds of remaining underweight perception. In contrast, overweight BMI students with losing weight intention were likely to continue with an overweight perception and transition from about the right weight to an overweight perception. Students who wanted to gain weight were more likely to remain underweight or change from underweight to about the right weight. Notably, students with more participation in muscle-strengthening exercises had a lower likelihood of remaining overweight perception. Both deep learning models have shown the top significant variables in Year 1 and Year 2 were weight change intention, BMI, skipped breakfast for losing weight, and days in muscle training exercises predicting third-year weight perceptions. The intention of losing weight, higher BMI status such as overweight and obese or unknown, and more days in skipping breakfast for losing weight predicted students towards an overweight perception. In contrast, among the right weight perception group, students tended to stay the same weight or not try to do any weight change, had healthy BMI, had a lower number of days skipping breakfast, and had more days in muscle training. These results were consistent with the weight perception transition-associated predictors from the Multinomial logistic regression. Conclusion As the first study that focused on Canadian youth behaviour profiles, prediction of BMI and weight perception incorporating multiple machine learning techniques, the result of the dissertation disseminates key messages to the stakeholders who want to understand student behaviour profiles and focus on the preventive intervention on youth obesity. This research emphasized the importance of the school’s environment on youth’s behaviour and the tri-directional relationships among BMI, weight change intention, and weight perception, suggesting future analysis to emphasize these variables when developing healthy behaviour-related strategies. Overall, it illustrated the necessity of establishing educational programs related to BMI and weight perception at school to raise awareness of self-esteem and body image acceptance.
EXPOSURE TO CANNABIS MARKETING IN THE UNITED STATES: DIFFERENCES BY CANNABIS LAWS AND THE STRENGTH OF RESTRICTIONS IN ‘RECREATIONAL’ CANNABIS MARKETS
(University of Waterloo, 2024-09-23) Winfield-Ward, Lauren Elizabeth; Hammond, David
Background: A growing number of U.S. states have legalized adult “recreational” cannabis. Restrictions on advertising and promotions to prevent marketing exposure among vulnerable populations are a key component of cannabis regulations in legal markets; however, there is little evidence on the impact of restrictions to date. Objectives: To examine differences in exposure to cannabis marketing across U.S. states where cannabis is illegal (‘illegal states’), legal for medical use (‘medical states’), and legal for recreational use (‘recreational states’). This study also examined differences in exposure by the strength of marketing restrictions among recreational states. Methods: Data are from the U.S. component of the International Cannabis Policy Study: repeat cross-sectional data from national surveys conducted with 187,573 respondents aged 16-65 over 6 annual survey waves (2018-2023). Exposure to cannabis marketing was assessed by asking respondents to report whether they have noticed any cannabis marketing across 11 channels in the past 12 months (‘noticing’ of cannabis marketing). The ‘strength’ of marketing restrictions was measured using data sourced from regulatory documents in each recreational state with legal sales and categorized into four strength levels. An index of the strength of marketing restrictions was then created for each recreational state with legal sales. Mixed effects logistic regression models (GLIMMIX) were fitted to analyze differences in self-reported noticing of cannabis marketing across medical and recreational policy changes, as well as by the strength of marketing restrictions in states with legal recreational sales. Analyses also examined exposure measures and associations with sociodemographic factors. Results: Self-reported exposure to cannabis marketing differed across policy changes. Noticing cannabis marketing was lowest in illegal states, with higher levels of noticing in states in the first 12 months following medical legalization (39.24% vs. 35.37%: AOR=1.16; 95% CI=1.01-1.33; p=0.034). Levels of noticing were higher in the first 12 months following recreational legalization relative to established medical markets (49.96% vs. 41.12%: AOR=1.41; 95% CI=1.34-1.48; p<.001), with additional increases 1-3 years and 4 or more years following the policy change (56.21%: AOR=1.20; 95% CI=1.14-1.25; p<.001, and 63.90%: AOR=1.21; 95% CI=1.16-1.27; p<.001, respectively). Noticing cannabis marketing also differed by the strength of restrictions in recreational states. In states with legal recreational sales, jurisdictions with the high (Level 3) restriction strength reported the lowest exposure to cannabis marketing (53.39% noticed), and exposure was similar across Level 1 and Level 2 restriction states. There was insufficient data to examine long-term trends for restriction levels. Conclusions: Self-reported exposure to cannabis marketing increases following medical and recreational cannabis legalization. Overall, stronger marketing regulations may reduce exposure in legal markets; however, underaged people report the greatest noticing of cannabis marketing. Research should continue to monitor trends in marketing exposure over time, as more states begin legal recreational sales and legal markets mature.
Estimating the proportion of hemolytic uremic syndrome cases in Shiga toxin-producing Escherichia coli cases – A systematic review and proportional meta-analysis
(University of Waterloo, 2024-09-23) De Silva, Udani; Majowicz, Shannon
Background: Shiga-toxin producing Escherichia coli (STEC) infection is a foodborne zoonotic infection causing a range of diseases, permanent injury and even death. STEC has been linked to large epidemics globally. While STEC can affect different organs of the human host, the kidneys are the primary site of pathological injury during infection. Hemolytic uremic syndrome (HUS) is a common sequela affecting the kidneys and can affect certain subpopulations disproportionately. This thesis aimed to estimate the cumulative incidence of HUS among symptomatic STEC cases, based on available data. Methods: I conducted a systematic review and meta-analysis to determine the overall and stratified cumulative incidence of HUS. I searched PubMed, Web of Science, Ovid® Embase and Scopus for published literature, followed by five grey literature databases, which were Google Scholar, INASP Journals Online project, OAIster, GreyGuide, and WHO IRIS. The inclusion criteria were human populations of all sociodemographic factors, as either confirmed or probable cases of symptomatic STEC infection. HUS was the condition of interest. Eligible records published in English, between 1 January 1990 and 14 January 2024 from all geographical regions were included. A second screener and I independently identified and included eligible studies in the systematic review. I extracted summary-level data on study information, STEC cases and HUS cases from included studies. A second reviewer and I assessed study quality of included records using tools by the Joanna Briggs Institute. To estimate the pooled cumulative incidence of HUS, I performed a random-effects meta-analysis for single proportions. To estimate the stratified cumulative incidence, I used subgroup analyses and meta-regression models for age, sex, STEC characteristics and study characteristics. Results: I identified 4,906 records from the literature searches, of which 269 studies (comprising 189,350 STEC cases aged 0 – 98 years) from 28 countries were included. The pooled cumulative incidence of HUS was 8.22% (95% CI, 7.82 – 8.61). In subgroup analyses, the cumulative incidence of HUS was highest among children aged between 0 and 4 years at 17.82% (95% CI, 14.57 – 21.07) and among female STEC cases at 13.03% (95% CI, 11.04 – 15.02). STEC O157 and co-infections with multiple serotypes were the most common serogroups among included studies. By study year, the highest cumulative incidence of HUS occurred between 2010 to 2014 at 14.79% (95% CI, 12.74 – 16.84). By study regions, the highest cumulative incidence of HUS was from the WHO European Region at 12.66% (95% CI, 11.47 – 13.85). The included studies were mostly high- quality studies. Age, sex, STEC serogroup, STEC genes, study year range and WHO Regions were significant predictors of cumulative incidence of HUS. Conclusion: The proportion of STEC cases that progress to HUS is relatively low. However, STEC cases are underestimated, and these proportions may overrepresent the true cumulative incidence estimates of the population. Some subpopulations had higher HUS incidence estimates, with age, sex, infecting STEC serogroup, STEC genes, study year range and region being significant predictors of STEC-HUS development. Thereby, these findings support current knowledge of STEC-HUS, provide important insights into STEC-HUS epidemiology, and can be used by clinical specialists and other stakeholders in research, policymaking and clinical guidance.

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