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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Cross-sectional Analysis of Current Care Assessment Practices in the Retirement Home Sector in Ontario
(University of Waterloo, 2025-11-06) Nasim, Anooshah
As the population of Canada ages, some older adults often have increased multimorbidity, disabilities, and frailty. As a result, they are at an increased risk of hospitalization, accelerated functional decline, and earlier institutionalization. As they face more disability and health challenges, the lack of sufficient primary, community, and home care services to support them leads many to move into retirement homes. Once there, residents continue to experience health challenges, likely as a consequence of ongoing inadequate primary care and insufficient services geared toward their needs. Yet, addressing the unmet needs of retirement home residents at the individual and population levels is made challenging by the lack of standardized information collection. While regulatory agencies stipulate that residents undergo a health assessment, there are no specific requirements as to their nature. A better understanding of their unmet needs can potentially guide better primary care planning and help identify the level of services required to deliver better resident and system outcomes. To begin, current care assessment practices and processes surrounding these assessments must first be characterized and understood before the introduction of a new standardized instrument can be contemplated.
Evaluating a priori and data-driven weighting of the Healthy Eating Food Index-2019 for assessing diet quality and gastrointestinal and aerodigestive cancer risk in Canadian adults
(University of Waterloo, 2025-10-23) Singh, Navreet
Background: Diet is a modifiable exposure implicated in gastrointestinal and aerodigestive cancers. Because foods are consucmed in combination, diet quality indices are used to summarize overall dietary patterns. The Healthy Eating Food Index-2019 (HEFI-2019) measures adherence to Canada’s Food Guide 2019, and its component scores are nearly equally weighted, reflecting the importance of all foods in a healthful dietary pattern. Its discriminatory capacity for measuring diet-disease associations, and the influence of the weighting schema of the index, remains uncertain. Objective: To assess whether associations between diet quality and gastrointestinal and aerodigestive cancer risk differ among adults in Canada based on the a priori Healthy Eating Food Index-2019 (HEFI-2019) versus a novel modified version with components reweighted using a data-driven approach. Methods: A prospective cohort analysis was conducted using the Canadian Community Health Survey 2004 Nutrition (CCHS 2004) linked with the Canadian Cancer Registry (CCR) through 2016. After exclusions, 10,530 adults were included, representing approximately 23.5 million Canadians. Diet was assessed using interviewer-administered 24-hour recalls. HEFI-2019 total scores were computed using standard weights and using data-driven weights derived from ridge-penalized Cox models in 10 iterations of 80/20 training–test splits with cross-validated penalty selection. Weighted Cox proportional hazards models, adjusted for age, sex, education, income, marital status, smoking status, body mass index, and alcohol consumption, estimated associations with incident gastrointestinal and aerodigestive cancers (ICD-9 140–149, 150–159, 160–161). Discrimination was assessed with Harrell’s C-index. Results: The data-driven approach altered component weights substantially (e.g., protein foods increased from 5 to 16.4; vegetables and fruits decreased from 20 to 3.73). No associations with cancer risk were observed for either the a priori (adjusted HR per unit increase 1.01; 95% CI: 0.99, 1.04) or reweighted HEFI-2019 scores (adjusted HR: 1.00; 95% CI: 0.98, 1.02). Model discrimination was similar (Harrell’s C-index: 0.81 [95% CI: 0.77, 0.85] for a priori; 0.87 [95% CI: 0.80, 0.93] for reweighted). Discussion: Neither the a priori nor reweighted HEFI-2019 was associated with gastrointestinal and aerodigestive cancer risk. Data-driven reweighting did not meaningfully improve associations or discriminatory capacity. These findings suggest challenges in using diet quality indices for complex diet-disease relationships and highlight the need for further research on index construction and application in cancer epidemiology.
Multi-Outcome Trajectories in Traumatic Brain Injury
(University of Waterloo, 2025-10-23) Shein, Vladyslav
Traumatic Brain Injury (TBI) presents a global health challenge, affecting millions of individuals annually, resulting in diverse outcome trajectories that complicate patient management. The heterogeneity in TBI outcomes, influenced by varied clinical presentations and injury responses, requires advanced analytical approaches. The analysis of trajectories using single metrics, such as the Glasgow Outcome Scale Extended Global (GOSE), falls short of capturing the multi-faceted nature of TBI progression, often overlooking the complexity of individual patient experiences. This thesis reports on two studies. First, a systematic scoping review was conducted to synthesize the current research on trajectory analysis in TBI, followed by a modeling study. This work identifies 6 distinct multi-outcome trajectories in TBI patients by employing Latent Class Mixed Models (LCMM) and clustering approaches. Utilizing longitudinal data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study (TRACK-TBI), a prospective multicenter observational cohort study conducted at 18 level 1 trauma centers across the United States, which includes 17 selected outcome measures collected at four time points post-injury, provides a comprehensive understanding of the heterogeneous progression of TBI. By addressing the limitations of single outcome analyses, this research contributes to a better understanding of TBI progression that can lead to the optimization of TBI management and treatment. The future integration of these trajectories will facilitate the development of personalized treatment strategies, ultimately improving patients’ recovery.
Socioeconomic Indicators and Psychopathology in Children with Chronic Physical Illness
(University of Waterloo, 2025-10-15) Khaira, Jothi
Background: Children with a chronic physical illness (CPI) have an increased risk of developing psychopathology. The combination of chronic stress and socioeconomic disadvantage often contributes to poor mental health in this vulnerable population of children. Research Questions: This study addresses the following questions: (1) Are neighborhood-level socioeconomic indicators worse among families of children with CPI compared to the general population? (2) Are these socioeconomic indicators associated with psychopathology among children with CPI over a 48-month period? (3) Does child stress moderate associations between socioeconomic indicators and child psychopathology over time? Methods: Data come from the Multimorbidity in Children and Youth across the Life-course (MY LIFE) study, which followed 263 children aged 2-16 years who had been diagnosed with a CPI, for 48 months. A one-sample t-test compared mean differences in socioeconomic indices, measured by the Ontario Marginalization Index (ON-MARG), between MY LIFE and the general population. Linear mixed models (LMMs) examined associations between ON-MARG dimensions and psychopathology symptoms, as measured with the Emotional Behavioural Scales. Moderation by child HCC was investigated using a time-varying product-term interaction. Results: At baseline, the study included 263 children with a CPI (mean age: 9.4 years, 53% male). Children in MY LIFE resided in areas characterized by greater socioeconomic disadvantage relative to the general population (M= -0.38- -0.20, p= <0.001). Material resources (β=0.13, p=0.03) and the two-way interaction between households and dwellings and time (β=0.02, p=0.04) were significantly associated with parent-reported externalizing symptoms. Households and dwellings (β=0.09, p=0.02) and the three-way interaction between age and labour force, time, and child stress (β=0.02, p=0.04) were significantly associated with child-reported externalizing symptoms. No significant associations were noted between ON-MARG dimensions and parent- and child-reported internalizing symptoms. Conclusion: Children with CPI were more likely to live in areas of high socioeconomic disadvantage with housing and material deprivation predicting elevated psychopathology symptoms. LMMs showed that time-varying child stress may have a moderating effect on indicators of socioeconomic disadvantage, particularly related to households and dwellings and material resources. Differences between parent- and child-reported models reinforce the importance of multi-informant perspectives. Findings highlight the need for integrated, equity-informed interventions targeting both socioeconomic and physiological drivers of child psychopathology among children with CPI.
Perceptions of Dementia among Young Arab Adults in Ontario
(University of Waterloo, 2025-10-06) Al-Saghier, Ruah
Introduction As dementia rates are projected to rise among ethnic communities in Canada, understanding how these communities perceive the condition is increasingly important (Alzheimer Society of Canada, 2024). This study focuses on young Arab adults due to the Arab population's rapid growth and relatively young age profile in Canada (Statistics Canada, 2022; Canadian Arab Institute, 2019). Given cultural expectations around caregiving, many of these individuals may assume caregiving roles for relatives with dementia in the future. Their perceptions are therefore critical, as they can influence caregiving approaches and help-seeking behaviors. While international studies suggest that Arab communities may hold negative views of dementia (Brijnath et al., 2021; Kane et al., 2021; Abojabel & Werner, 2019), there is limited research exploring these perceptions within the Canadian context. Objective The objective of this qualitative study is to explore the perceptions of dementia among young adults between the ages of 18 and 30 who are members of Arab communities in Ontario. The research question is ‘how do young Arab adults perceive dementia?’. Methods This study recruited 10 young Arab adults and conducted in-depth, semi-structured interviews with each participant. Although the participants were provided with the choice of having an Arabic or English interview, all the participants opted for an English interview. Two interviews were conducted in-person and eight were conducted online. The study used reflexive thematic analysis to analyze the data using a software called MAXQDA. Findings Three themes were generated from the reflexive thematic analysis. The themes provided an idea on how the participants and their communities perceive dementia. The three themes were: Describing dementia, Understanding the causes of dementia, and Living with dementia. The themes shared a range of different perceptions, which may be a reflection of the differences between the participants and their communities. The participants highlight many perceptions that were rooted in religious or spiritual beliefs – highlighting the importance of religion to the community. Overall, many perceptions reflect some stigma in how participants and their community view dementia, such as the hesitancy to use the word dementia or the negative language used to talk about dementia. Implications This study shows the value of developing dementia resources that are both culturally and spiritually sensitive for Arab communities. Involving community members in co-creating educational tools, working with places of worship, and acknowledging the role of cultural beliefs in shaping care can help make public health efforts more effective. As for future researchers, there is a pivotal need to include Arabs living with dementia in Canadian research.
Examining the Association between Functional Social Support, Marital Status, and Memory in Middle-Aged and Older Adults in Canada: A Mixed Methods Study
(University of Waterloo, 2025-09-29) Haghighi, Paniz
Although several studies have found that functional social support (FSS) promotes memory through stress-buffering mechanisms, the role of marital status in shaping this association remains underexplored. This thesis – a sequential explanatory mixed-methods study – is the first research to examine whether marital status modifies the association between FSS and memory in community-dwelling, middle-aged and older adults (45-85 years old). Data for the quantitative portion of the study were obtained from the Tracking Cohort of the Canadian Longitudinal Study on Aging (CLSA). Memory was regressed on FSS, adjusting for various sociodemographic, lifestyle, and health-related covariates, in a linear mixed effects model. The moderating effect of marital status was assessed by adding its interaction with FSS to the model. Results showed significant and positive adjusted associations for overall FSS (β: 0.07; 95% CI: 0.01, 0.13) and two FSS subtypes, namely positive interactions (β: 0.06; 95% CI: 0.01, 0.11) and affectionate support (β: 0.05; 95% CI: 0.00, 0.11), with memory. However, the interaction between marital status and FSS (overall and subtypes) was not statistically significant (likelihood ratio test p-value = 0.75), indicating that FSS did not have differing effects on memory according to marital status. Two sensitivity analyses – one stratifying the sample by baseline marital status and another comparing different missing data approaches – confirmed the initial findings. For the qualitative portion, semi-structured interviews were conducted with a sample of 18 community-dwelling adults who resembled the CLSA population and reported different categories of marital status. Each interview was audio recorded, transcribed verbatim, and thematically analyzed with the goal of explaining and contextualizing the quantitative results. Three major themes emerged from the interviews to help explain why marital status, contrary to a priori expectations, did not impact the FSS-memory association: “learning to cope” – participants used other alternatives besides a spouse to deal with memory challenges; “context matters” – contextual factors such as marital quality may affect this association; and, “doing more harm than good” – some spouses may provide too much support, reducing participants’ autonomy to stimulate their own cognitive processes. The thesis findings highlight the complexity of marital relationships and emphasize the need to consider factors such as satisfaction with one’s marital status and adequacy of support to provide a comprehensive understanding of how social and marital dynamics impact cognitive trajectories. This research suggests public health initiatives focused on enhancing social support could promote cognitive health in aging populations, regardless of marital status.
Stroke in Young Adults: A Multifactorial Case-Control Analysis of the Established and Emerging Risk Factors
(University of Waterloo, 2025-09-17) Singh, Sanewal
While the incidence of stroke continues to decline among older adults in most parts of the world, stroke rates in younger adults have shown a concerning rise. Despite growing awareness and research, the etiology and risk profiles of stroke in young adults remains poorly understood and often explained using studies focused on older populations. However, applying findings from older adults to younger populations may be limited, due to given substantial differences in lifestyle and health risk factors. To better understand the rise of stroke in young adults, this thesis utilizes a case-control study design with primary data to investigate the sociodemographic, behavioural, and clinical characteristics of stroke in young adults. This thesis includes a four-paper approach. The first study provides a comprehensive descriptive analysis of young adult stroke survivors, with a comparison to healthy adults within the same age range. The purpose of this study is to identify the sociodemographic attributes (e.g., race, education level, income), lifestyle factors (e.g., exercise, diet), health conditions (e.g., hypertension, heart conditions), and unique risk factors to young adults (e.g., caffeine consumption, mental health). Additionally, this study examines the temporal patterns of comorbidities in relation to stroke occurrence. Thereby, this study distinguishes between pre-existing and post-stroke diagnoses, and thus provides temporal insight into identifying prevalent risk factors and those that may go undiagnosed. The second study uses a multiple conditional logistic regression analysis to explore the associations between a broad range of established and emerging risk factors and stroke risk in young adults. This paper expands on previous research by considering risk factors that may be unique to young adults, such as mental health conditions, substance use, and certain lifestyle factors. This paper challenges the direct application of risk factor analyses developed among older adults, underscoring the importance of age-specific research. The third study examines the relationship between caffeine intake and stroke risk in young adults. Specifically, this paper examines the overall association between daily caffeine consumption and stroke risk, as well as the dose-and source-specific impact (e.g., coffee, tea, energy drinks, soda). Notably, this study approaches the intake of caffeine and various sources as a non-linear association, which is often overlooked in the progression of cardiovascular disease. Given that caffeine is widely consumed in young adults, this study offers new perspectives into how it may influence cerebrovascular health amongst this population. Study four highlights the challenges of recruiting participants from rare or uncommon populations and presents a key methodological contribution of this thesis. Specifically, it examines the challenges of using traditional methods of recruitment, such as polling firms or clinical settings, which are often costly, time consuming, and limited in their reach. This paper demonstrates the use of social media as a cost-effective solution to the aforementioned recruitment challenges, using young adults who have experienced a stroke as an example. Nonetheless, study four highlights the key considerations for researchers planning on using social media for recruitment of rare or uncommon populations, while also acknowledging its limitations. Together, this thesis seeks to provide a novel, multifactorial analysis of stroke risk in young adults by incorporating both established and emerging variables, as well as focusing on age-specific risk factors. In addition, this thesis offers a key methodological contribution to the field of stroke research by demonstrating the effective use of social media for recruiting uncommon populations and by capturing temporal patterns of health conditions related to stroke onset. Overall, this thesis aims to advance the current understanding of stroke risk in young adults and highlights the need for prevention and clinical strategies specific to their unique risk profiles.
MAPPING BARRIERS AND SUPPORTS: A QUALITATIVE EXPLORATION OF INTERNATIONAL STUDENTS’ ACCESS TO MENTAL HEALTH AND SOCIAL SERVICES IN THE WATERLOO REGION
(University of Waterloo, 2025-09-11) Madhani, Alyssa
Introduction: International students face numerous challenges when accessing mental health and social support services while studying abroad. These challenges are often compounded by cultural transitions, systemic barriers, academic pressure, and unfamiliar institutional environments. This thesis explores how international students in the Waterloo region experience and navigate access to mental health and social services, as well as how service providers perceive and respond to these needs. Methods: This study employed a qualitative thematic narrative design to capture the lived experiences of international students and the insights of institutional service providers. Data were collected through semi-structured interviews with 14 international students and 3 service providers affiliated with local postsecondary institutions. Interviews were transcribed verbatim and analyzed using inductive thematic analysis, guided by the Health Belief Model (HBM), the Transactional Model of Stress and Coping, and Ecological Systems Theory. Results: Through an inductive coding process, I identified six key themes from the data: Cultural Adaptation, Mental Health Access, Academic Pressure, Financial Constraints, Professional Growth and Community Building, and Institutional Roles and Service Gaps. These themes were organized into two overarching domains—Student Experiences and Institutional Responses—which revealed both alignment and divergence between international students lived experiences and service providers’ institutional perspectives. Common barriers included long wait times, cultural mismatch, financial burden, and difficulties navigating institutional systems. Students emphasized emotional impact and interpersonal disconnect, while providers often focused on structural limitations and programmatic efforts. Conclusion: Findings highlight the complex interplay between personal, cultural, and institutional factors shaping international students' access to mental health and social services. Addressing these issues requires multi-level interventions that prioritize cultural responsiveness, institutional transparency, and proactive support. This study contributes to a growing body of research advocating for equity-oriented improvements in international student support infrastructure across postsecondary contexts.
The Mediating Effect of Functional Social Support in the Pathway between Memory and Depressive Symptoms: A Longitudinal Mediation Analysis of the Canadian Longitudinal Study on Aging
(University of Waterloo, 2025-09-09) Modebelu, Ifunanya
Background: Cognitive function and emotional wellbeing are essential for healthy aging. Cognitive impairment and depressive symptoms can lead to severe morbidity and mortality in aging adults. Strong, positive associations exist between memory impairment – memory is a subdomain of cognition – and depressive symptoms. Evidence also suggests one’s perceived level of functional social support (FSS) may affect the emergence of depressive symptoms in aging adults with memory impairment. However, few studies have explored whether FSS mediates the association between memory and depressive symptoms. Methods: This research utilized an analytical sample drawn from 21,241 participants between the ages of 45 and 85 years who were enrolled in the Tracking Cohort of the Canadian Longitudinal Study on Aging (CLSA) at baseline. The thesis examined three aims: the association between memory and depressive symptoms across three time points of data (baseline, three-year follow-up, and six-year follow-up), controlling for health, lifestyle, and sociodemographic covariates; the potential mediation effect of FSS on this association; and whether moderated mediation was present by age group and sex. Results: Overall, memory function was inversely associated with depressive symptoms (β ̂ = -0.08; 95% confidence interval [CI]: -0.11, -0.04). The indirect (mediated) effect of memory on depressive symptoms through FSS was statistically significant, though minimal (β ̂ = -0.02; 95% CI: -0.02, -0.01), and most of the effect was direct (β ̂ = -0.07; 95% CI: -0.10, -0.04). No evidence existed for statistically significant moderated mediation by age group or sex. Contribution: This novel research suggested that functional social support may mediate the association between memory and depressive symptoms. Further research is required to advise health practitioners who deal with memory-impaired individuals as to whether interventions promoting functional social support (e.g., social prescribing) can help minimize symptoms of depression.
Investigating the Impacts of Policy Stringency on the Public Perceptions of Pandemic Policies, Sentiment Analysis of Tweets During the Second and Third COVID-19 Pandemic Waves in Ontario
(University of Waterloo, 2025-09-09) Grigg, Bailey Marie
Background: Public sentiment plays a critical role in shaping compliance and trust during public health crises. The COVID-19 pandemic was the first example of an infodemic, and the significant amount of social media data from that time period can be useful for understanding public responses and experiences throughout the pandemic. This study explores emotional responses to COVID-19 policy interventions in Ontario, Canada, using Twitter data to assess how public sentiments varied across lockdowns, mask policies, and vaccine mandates. The research aims to understand how policy stringency and a regional context influenced public attitudes throughout the pandemic. Methods: Data from the Twitter API was collected and analysed. Tweets posted between December 1st, 2020 and June 30th, 2021 from app users in Ontario were compiled and sorted using zero-shot classification into subgroups for relevant categories – vaccine mandates, mask policies, and lockdown measures. These tweets were then analyzed using sentiment analysis and the COVID-19 Stringency Index to identify trends in the sentiments expressed on Twitter over time, considering changes in the strictness of various pandemic measures. Results: Initial temporal analysis identified key events that led to notable sentiment changes, such as sentiment spikes following the announcement of the CERB program in March, followed by lockdown sentiments declining sharply in April after the use of the “provincial emergency brake”. Lockdown sentiments remained consistently neutral to negative, with no significant threshold effects or time-based recovery. Vaccine mandates showed a positive shift in sentiment beyond identified stringency breakpoints, with further improvement over time. Mask mandates initially received positive sentiments but declined sharply after passing a stringency threshold. Ottawa Twitter users expressed more positive and emotionally reactive sentiment than Toronto users, particularly in response to lockdown and vaccine policies. Conclusion: Social media data offers valuable insight into public sentiment dynamics during health emergencies. Findings suggest that policy framing and perceived intrusiveness significantly influence emotional responses, with vaccine mandates benefiting from proactive messaging and civic framing. Regional differences underscore the importance of localized communication strategies. These results can inform future public health interventions by emphasizing the role of timing, tone, and threshold sensitivity in shaping public trust and engagement.
Marketing of unhealthy foods and beverages to youth: an investigation of domestic and international approaches to child-directed marketing restriction
(University of Waterloo, 2025-09-02) Boyar, Yelyzaveta
Background Diet quality during childhood is a critical factor for healthy growth and development. Children are vulnerable to food marketing, which impacts nutrition behaviours by influencing product awareness, attitudes, and purchasing intent. Restrictions on marketing of unhealthy foods to children are a potential population-level policy implemented in several countries. In Canada, marketing practices are guided by voluntary industry self-regulation; Québec is the only province which has mandatory restrictions on child-directed advertising (the Consumer Protection Act). In 2023, Health Canada proposed new regulations to restrict advertising of foods that contribute to excess intakes of sodium, sugars, and saturated fat to children under 13 years of age across some media and settings. Scientific literature on the effectiveness of mandatory marketing restrictions is mixed. Few studies have examined Québec’s existing provincial advertising law and there is limited evidence on nuanced components of marketing restrictions, including ‘brand-only’ marketing (i.e., marketing that relies solely on attributes recognizable as a representation of the brand, such as logos or mascots, without any identifiable food/beverage products). Additionally, though several countries require messages promoting healthy diet and exercise to be displayed on advertisements for unhealthy foods as an alternative policy measure, their potential to mitigate the promotional influence of advertisements is currently not well understood. Research Objectives The overall objective of this thesis was to examine key characteristics of policies restricting food marketing to children that may strengthen or weaken policy impact. This was done using three sub-studies. Study 1 sought to compare self-reported exposure to child-directed unhealthy food marketing among youth in Québec (which has mandatory restrictions on child-directed advertising) to youth in the other Canadian provinces where no mandatory marketing restrictions exist. Study 2 sought to examine the impact of ‘brand-only’ marketing, which would be permitted under proposed federal regulations in Canada, on product appeal and selection among youth. Study 3 sought to examine the efficacy of public health messages displayed on sugar-sweetened beverage (SSB) advertisements on advertised product appeal and perceived healthiness among youth. Methods The three studies were conducted as part of the International Food Policy Study (IFPS) Youth Surveys, which are annual cross-sectional surveys conducted online in Australia, Canada, Chile, Mexico, the United Kingdom, and the United States with youth aged 10-17 years. Study 1 used an observational design, consisting of cross-sectional analysis of data from 15,199 youth in Canada (n=3,757 in Québec) only. Survey waves 2019-2022 assessed self-reported exposure to unhealthy food marketing, including marketing locations, marketed products, marketing techniques, brands marketed, perceptions of marketing as targeting children under 13, and desire to consume advertised products. Logistic and linear regression models investigated differences by geographic jurisdiction, adjusting for age, sex-at-birth, race or ethnicity, perceived income adequacy, screentime, and survey year. Studies 2 and 3 both used experimental designs and were embedded within the 2023 IFPS Youth Surveys for all six countries. Study 2 consisted of a between-group experimental design conducted with 5,744 youth. Participants were randomised to view an advertisement according to one of four conditions: control (video game), ‘brand-only’ (McDonald’s logo), ‘brand and unhealthy food’ (McDonald’s logo and hamburger), and ‘brand and healthy food’ (McDonald’s logo and salad). Logistic and linear regression models tested the effect of ‘brand-only’ marketing on product appeal (measured through desire to consume the advertised product) and self-reported menu item selection in a hypothetical product selection task, as compared with other conditions. Study 3 consisted of a between-group 2-by-2 experimental design conducted with 11,521 youth. Participants were randomised to view one of two SSB advertisements (soda or a fruit drink) either with or without a health message. Logistic and linear regression models examined the efficacy of health message presence on advertised product appeal (measured through desire to consume the advertised beverage) and perceived healthiness, including 2-way interactions between beverage type and message presence. Results Study 1: Compared to youth in other provinces, Québec youth reported seeing advertisements for unhealthy foods in fewer locations (β: -0.46), and for fewer beverage (β: -0.18) and restaurant brands (β: -0.15; p<0.001 for all); this was true across marketing locations regardless of whether they were covered under restrictions. Québec youth also reported seeing advertisements for sugary drinks (β: -0.40), fast-food (β: -0.30), sugary cereals (β: -0.38), snacks (β: -0.27), and desserts/treats (β: -0.28; p<0.001 for all) less frequently than those in other provinces. Québec youth had lower odds of reporting seeing advertisements featuring child-appealing marketing techniques including cartoons/characters (adjusted odds ratio (AOR): 0.57), celebrities (AOR: 0.57), unhealthy food/drink company branding (AOR: 0.75), and restaurant toys (AOR: 0.53; p<0.001 for all). Québec youth had lower odds of identifying beverage brand advertisements as ‘usually aimed at kids 12 and under’ (AOR: 0.72, p<0.001) and reported less desire to consume branded beverages than youth in other provinces (β: -0.10, p=0.002). Overall, youth’s self-reported exposure to unhealthy food and beverage advertisements was substantially lower in Québec, the only Canadian province with mandatory restrictions on child-directed advertising. Study 2: No differences by condition were observed for product appeal (F=2.0, p=0.111). In terms of menu item selection, youth who were randomly assigned to view the ‘brand and healthy food’ advertisement were more likely to select the Garden Salad (5.7%; product featured in ‘brand and heathy food’ condition and only menu item meeting marketing nutrient profile model thresholds) than those in the ‘brand and unhealthy food’ (3.8%, odds ratio (OR):1.53) and ‘brand-only (3.5%, OR:1.49) conditions (p<0.05). Youth in the ‘brand and healthy food’ condition also selected items with less saturated fat and calories than those in the ‘brand and unhealthy food’ (saturated fat β: -0.66; calories β: -25.50) and ‘brand-only’ (saturated fat β: -0.62; calories β: -26.06) conditions (p<0.01 for all). Moderate-to-weak evidence suggests that youth in the ‘brand and unhealthy food’ condition (17.5%) were more likely to select the Quarter Pounder Deluxe (product featured in ‘brand and unhealthy food’ condition) than those in the ‘brand and healthy food’ (14.2%, OR: 1.29, p=0.013) and ‘brand-only’ (15.0%, OR: 1.20, p=0.068) conditions. Overall, brand-only advertisements likely have similar impacts on youth’s selection of unhealthy products as advertisements featuring unhealthy foods, whereas advertisements featuring healthy products may increase selection of healthier items. Study 3: No differences in advertised beverage appeal were observed by health message presence (F=1.13, p=0.287). Youth who saw an advertisement with a health message rated the advertised beverage as healthier (mean:1.60) than those who saw an advertisement without a health message (mean:1.54, β:0.06, p=0.001). Health message presence slightly increased perceived healthiness for fruit punch (β: 0.09, p=0.002) but not Sprite (p=0.171); however, there was no evidence of an interaction between SSB beverage type and message presence for either perceived healthiness (F=1.68, p=0.195) or appeal (F=1.13, p=0.288). Overall, health messages may be ineffective in discouraging unhealthy food consumption and may even erroneously reinforce perceptions of SSBs as healthy. Contribution/Significance The findings provide evidence in support of mandatory marketing policies having a protective effect, while highlighting the need to include brand-only marketing in marketing regulations. The results also suggest that health messages may not be an effective regulatory alternative to marketing restriction. Priorities for future research include: 1) observational research with Anglophone and Francophone youth across Canada, including robust sample sizes of non-dominant language speakers in each province, to discern language-related differences in child-directed marketing exposure; 2) experimental studies using ‘real world’ selection tasks to assess impact of brand-only and healthy food advertisements on menu item selection across a variety of brands and food processing levels; and 3) experimental studies investigating whether framing and design of health messages according to best practice guidelines may increase message efficacy. Overall, this thesis provides timely evidence to inform efficacy of policies seeking to restrict marketing of unhealthy foods to children in Canada and abroad.
Exploring Food Insecurity as a Risk Factor for Eight Enteric Infections in Ontario, Canada, 2019-2022: Multilevel Ecological Study
(University of Waterloo, 2025-08-28) Hammond, Jacob
Food insecurity and foodborne illness are significant public health issues in Canada, associated with poor health, direct healthcare costs, and lost productivity. While previous ecological studies in higher-resource countries have explored the relationship between broad socioeconomic determinants and foodborne infections, none have explored food insecurity as a risk factor for enteric infections. Food insecurity is recognized as a potential intermediary determinant that can influence an individual’s vulnerability and exposure to foodborne illness. This study aimed to identify the magnitude, distribution, and spatial patterns of reported Campylobacter spp., Salmonella spp., Shiga toxin-producing E. coli (STEC), Listeria monocytogenes., Shigella spp., Cyclospora cayetanensis, Giardia duodenalis spp., and hepatitis A virus infections across Ontario, Canada, from January 2019 to December 2022. Additionally, it explored whether age- and sex-adjusted annual pathogen-specific incidence rates were associated with the prevalence of household food insecurity at the Public Health Unit (PHU) level during 2021. Public Health Ontario’s publicly available surveillance tools were used to collect data on household food insecurity and reported case counts of eight enteric infections for 34 Ontario PHUs. Annual age- and sex-adjusted pathogen-specific incidence rates were calculated for each PHU using direct standardization and were visualized using choropleth maps. Purely spatial, temporal, and space-time high infection rate clusters were identified using retrospective scan statistics, with a Poisson model. Global and local spatial autocorrelation patterns of annual pathogen-specific incidence rates were examined using the Moran’s I spatial statistical method. Fixed and random effects Poisson and Negative Binomial regression analyses were conducted to estimate incidence rate ratios (IRR) for each enteric pathogen and the prevalence of household food insecurity, while controlling for demographic and socioeconomic covariates. A geographically weighted Poisson regression analysis was used to explore whether the association between pathogen-specific incidence rates and household food insecurity differed spatially across PHUs. Reported cases of all enteric pathogens, except for Listeria monocytogenes, had a noticeable decline after 2019. Campylobacter spp., Salmonella spp., and Giardia duodenalis consistently had the highest incidence rates across PHUs from 2019-2022. Spatial and spacetime analyses showed that Salmonella spp. and STEC high-infection rates mainly clustered in Central- and South-West regions of Ontario. Campylobacter spp., Listeria monocytogenes, Shigella spp., Cyclospora cayetanensis, Giardia duodenalis, and hepatitis A infections were widely distributed across the province. Campylobacter spp., STEC, Listeria monocytogenes, and Cyclospora cayetanensis were the only pathogens to exhibit a temporal pattern, with infections clustering in the warmer months. Two significant space-time clusters of Salmonella spp. and hepatitis A were associated with confirmed outbreaks in Lambton Public Health and Middlesex London Health Unit. In 2021, the prevalence household food insecurity had an inverse association with the incidence rates of Campylobacter spp., STEC, and Giardia duodenalis, with minimal spatial variability of the IRRs across PHUs. No significant associations were observed between household food insecurity and the other enteric pathogens. Food insecurity may influence the incidence of foodborne illness at an aggregate level. Spatial and temporal clustering of enteric pathogens suggests local and seasonal risk factors could be associated with foodborne illness. Future research should investigate whether the incidence rates of foodborne illness differ among populations experiencing marginal, moderate, and severe levels of food insecurity. The findings from this study could help PHUs develop public health interventions that simultaneously address food insecurity and food safety.
Investigating socioeconomic inequities in diet quality among adults in Canada using an intersectional approach
(University of Waterloo, 2025-08-27) Doan, Natalie
It is well-acknowledged that diet quality differs across socioeconomic position (SEP). However, it is unclear how SEP dimensions intersect to shape diet quality. My dissertation uses an intersectional approach to identify differences in diet quality across SEP dimensions and contexts. The primary objectives of my dissertation research were: (1) to identify individual/household SEP intersections that best predicted lower and higher diet quality among a population-based sample of adults in Canada; (2) to assess whether four dimensions of neighbourhood deprivation were independently and/or jointly associated with diet quality among a nationally representative sample of adults in Canada; and (3) to compare associations between three SEP indicators (educational attainment, perceived income adequacy, household food insecurity) and diet quality between adults in Canada and the United States. In a conditional random forest analysis, I identify educational attainment and Indigenous identity and race/ethnicity as the most important intersectional predictor of diet quality among adults in Canada. By examining four dimensions of neighbourhood deprivation, I find significant interactions that suggest associations between living in a neighbourhood with less material resources and lower HEI-2015 scores was stronger in areas with a smaller proportion of recent immigrants/visible minorities and non-working individuals. In a cross-country comparison, I find that associations between SEP (educational attainment, perceived income adequacy, and household food insecurity) and diet quality did not differ between Canada and the United States. Overall, this dissertation demonstrates how an intersectional approach to quantitative health research can be used to draw attention to the complex and context-dependent nature of inequities in diet quality.
"Superior by nature"?-Diagnosing dementia in northwestern Ontario
(University of Waterloo, 2025-08-26) Wheeldon, Katelyn
In 2025, Canada is home to approximately 771,939 people living with dementia and Ontario is projected to have the most new cases by province in the country by 2050. Northern Ontario makes up over 90% of the province’s landmass and has 6% of its population. In Northwestern Ontario specifically, there is a higher proportion of people over the age of 65 compared to the rest of the province. This is important because prevalence of dementia nearly doubles every five years after the age of 65, meaning a population more at risk of developing dementia. Rural and remote communities in the northwest region are struggling to meet the basic healthcare needs of their residents. The Ontario Medical Association has labeled the state of the healthcare in this region a ‘crisis’ (n.d.(b)). This research explored the experiences of giving and receiving a diagnosis of dementia from the perspectives of physicians and caregivers of people living with dementia in northwestern Ontario. Existentialist phenomenology was utilized to uncover shared meanings and understandings about the diagnosis process, particularly how these experiences are situated in a remote and rural context. There were significant system gaps that impacted the experience of caregivers of people living with dementia and physicians in northwestern Ontario. Not being heard by physicians damaged relationships between caregivers and the healthcare system and created feelings of mistrust, frustration, and isolation. Physicians managed the emotional work of dementia diagnoses in private while working to overcome system shortages that impacted their ability to care for people living with dementia. However, despite the tension in relationships between physicians and caregivers, they often cited similar healthcare challenges that greatly impacted good dementia care. The struggles plaguing the healthcare system in northwestern Ontario appeared to impact everyone involved in dementia diagnoses, and both caregivers and physicians were committed to overcoming challenges and providing the best care possible for people living with dementia.
Dementia Dastan: Understanding the Experiences of South Asian Canadians Living with Dementia and their Care Partners
(University of Waterloo, 2025-08-25) Gill-Chawla, Navjot
Abstract Introduction As Canada faces the growing challenge of dementia, there is an urgent need to ensure that care and support systems are responsive to the country’s increasingly diverse population. While Canada’s multicultural landscape has shaped many aspects of healthcare, the specific needs of diverse communities, such as South Asian Canadians, remain insufficiently addressed. Cultural stigma, language barriers, and a lack of culturally tailored resources continue to delay dementia recognition, diagnosis, and access to appropriate care for many in this population. While some experiences of individuals living with dementia and their care partners, such as navigating healthcare systems and dealing with the emotional toll of caregiving, are common across communities, South Asian Canadians face additional culturally specific challenges. These include stigma rooted in cultural beliefs, language barriers, and limited access to services designed to align with their cultural values. Despite strong caregiving traditions within South Asian families, limited Canadian research examines both the shared and culturally specific aspects of their experiences. This thesis examines the lived experiences of individuals with dementia, their care partners, physicians diagnosing dementia, and employees of community support organizations to identify barriers, strengths, and strategies for improving culturally inclusive dementia care while highlighting universally shared experiences. Methods This research employs a qualitative, interpretive phenomenological approach through three interconnected studies conducted across Canada in Alberta, British Columbia and Ontario. Study 1 examines the experiences of 16 participants (14 care partners and two individuals living with dementia) across the stages of recognizing symptoms, obtaining a diagnosis, and accessing services. Study 2 examines the perspectives of 13 physicians on diagnosing dementia in South Asian Canadians, while Study 3 gathers the insights of 14 employees from community support organizations that provide dementia services. Semi-structured interviews were conducted in English for Studies 2 and 3 and in English, Hindi, and Punjabi for Study 1. Reflexive thematic analysis was applied to identify recurring and distinct themes across participant groups. Results Key findings are organized into themes within each study. Study 1 identified barriers and stigma in recognizing dementia, challenges in obtaining a diagnosis, accessing services post-diagnosis, and transitioning to long-term care. Cultural beliefs often delay symptom recognition, while stigma prevents families from seeking early intervention. Limited familiarity with healthcare systems and a lack of culturally sensitive resources further complicates the care process. Study 2 revealed themes related to barriers to dementia diagnosis, cultural and generational influences, communication and disclosure, and the improvement of inclusivity and resources. Physicians highlighted language barriers, cultural sensitivities, and the absence of tailored diagnostic tools as significant challenges. Study 3 identified themes of cultural sensitivity in service delivery, engaging with South Asian communities, challenges in delivering services, and future directions. Community support employees emphasized the importance of cultural humility, trust-building, and partnerships with cultural organizations while noting systemic funding gaps. Conclusion This research demonstrates the critical need for integrating culturally sensitive care into dementia care practices and policies to address the unique barriers faced by South Asian Canadians. Findings underscore the importance of early and accurate diagnosis, community engagement, and the development of culturally and linguistically tailored resources to support families. Strong familial networks and caregiving traditions within South Asian communities can serve as foundations for interventions that enhance access to services and reduce stigma. Systemic changes, including increased funding for the development and implementation of culturally sensitive resources and programs, are essential to achieving equitable dementia care. By addressing cultural and systemic barriers, this thesis contributes actionable insights that aim to inform dementia care that meets the needs of Canada’s increasingly diverse population.
“I am in total control in my kitchen”: Food Safety Risk Perceptions of Independently Living Older Adults in Southern Ontario, Canada
(University of Waterloo, 2025-08-25) Sarwal, Kanika
Background: Foodborne illness is a significant global public health concern. Older adults are particularly vulnerable to foodborne illness due to age-related physiological changes, including weakened immune systems and chronic health conditions. In Canada, approximately four million cases of foodborne illness occur each year, resulting in over 240 deaths. While the aging population is rapidly growing, there is limited research on how older adults who live independently perceive and manage food safety risks. The overall aim of the thesis was to understand how independently living persons aged 65 and older, living in Southern Ontario (Kitchener-Waterloo, Cambridge, Guelph, and Woodstock) perceive and mitigate their risks of foodborne illness in their home environments. Specifically, the objectives were to explore: (i) how and why these individuals perceive their risk of developing foodborne illness, and (ii) whether these individuals follow recommended food safety practices and why or why not. Methods: I conducted 14 semi-structured interviews with persons aged 65 and older, who live independently in Southern Ontario, speak English, and are primary food preparers in their households. Participants were primarily recruited using flyers at community centres for older adults, a health fair hosted at one of these centres, the Schlegel-UW Research Institute for Aging, libraries, and religious institutions. The interview guide was informed by the World Health Organization’s Five Keys to Safer Food. Each interview lasted 45-60 minutes and was conducted in person (n=10) or virtually (n=4). In-person interviews were audio recorded using Microsoft Teams, while virtual interviews were both audio and video recorded using Zoom, and live transcription was enabled on both platforms. I manually transcribed each recording verbatim and carefully revised the auto-generated transcriptions for accuracy. This study used a post-positivist and interpretive theoretical orientation. I analyzed the data using a combination of inductive and deductive approaches through reflexive thematic analysis, following Braun & Clarke’s six-phase process. Results: Four themes were developed using an inductive approach based on the interviews with older adults: (1) Trusting my own cooking, (2) Doing what I’ve always done, (3) Being conscious of minimizing food waste, and (4) Cooking is a chore. Each theme encompassed subthemes that illuminated their nuanced perspectives and experiences. Participants expressed strong trust in their own food handling practices at home, which contributed to their perception of being at low risk for foodborne illness. They believed that preparing healthy meals makes their food naturally safe, leading them to believe that illness is unlikely to affect them. They engaged in varied food handling practices; some followed recommended guidelines, while others deviated, such as not using a food thermometer. Their practices were shaped by long-standing habits, experience, and reliance on both their food safety knowledge and their social networks. Participants described shopping and food preservation strategies aimed at minimizing food waste and costs, which resulted in neglecting best practices. In addition, limited kitchen space affected their food choices and storage practices. Reduced motivation to prepare meals and physical limitations prompted them to adjust their preparation methods and rely on convenience. Conclusion: This is the first study in Canada to explore older adults’ perceptions of food safety risks using semi-structured interviews. While participants demonstrated solid food safety knowledge, they perceived themselves at low risk for foodborne illness in their homes. The findings highlight the need for education and awareness of specific food handling practices. This study provides practical guidance for public health professionals and senior care organizations to develop tailored resources that promote safe food handling, support older adults’ independence, and bridge the gap between knowledge and practice to reduce their risk of foodborne illness.
Alert Systems for Missing Persons Living with Dementia: From Policy to Implementation
(University of Waterloo, 2025-08-21) Adekoya, Adebusola
Background: People living with dementia are at risk of going missing and experiencing serious harm. Alert systems, such as the BC Silver Alert in Canada, Silver Alert in the United States, and Purple Alert in Scotland, use mobile apps or media to notify the public and assist in locating missing persons with dementia. Policies regarding alert systems exist in the United States. Two Canadian provinces mention Silver Alert in Missing Persons Acts, but these legislations are not associated with implementation of these systems. Little is known about how alert systems for older adults are implemented and adopted, specifically in Canada. Objectives: This dissertation examined the development and implementation of alert systems for missing persons with dementia across Canada, Scotland, and the United States through three studies. Study 1 explored user experiences implementing alert systems and related policies, drawing on stories and insights from individuals who went missing, their care partners, and those involved in search efforts. Study 2 examined the conditions surrounding alert system implementation, using the Knowledge-to-Action (KTA) Framework. Study 3 explored multi-level factors influencing implementation of alert systems, guided by the Consolidated Framework for Implementation Research (CFIR). Methods and Results: Using a multiple case study design, data were collected through policy document review, interviews, and focus groups with 40 stakeholders, including people with lived experience, first responders, service providers, policymakers, technology developers, and researchers. Data from the three studies were analyzed using thematic analysis. Study 1 underscored the importance of stakeholder engagement, legislative support, timely police reporting, coordinated search efforts, and public education in implementing alert systems and locating missing persons. The findings also highlighted the emotional impact of missing incidents on people living with dementia and their care partners and challenges such as inaccurate tips, which can delay search efforts. Study 2 findings revealed variability in alert system implementation and related policies and identified individual and organizational barriers, including limited understanding, privacy concerns, alert fatigue, sustainability, and accessibility. Findings from Study 3 identified key factors influencing alert systems implementation across CFIR domains: Intervention Characteristics (relative advantage, evidence strength and quality, cost), Outer Setting (end user needs and resources, cosmopolitanism, external policy and incentives), Inner Setting (culture, available resources), Characteristics of Individuals (knowledge and beliefs about the intervention), and Implementation Process (planning, engaging stakeholders, reflecting and evaluating). Findings from the three studies emphasize the importance of integrated implementation of alert systems that actively engage stakeholders, address contextual factors and challenges, and ensure equitable access for all users. Contributions: This dissertation provides an understanding of how current alert systems and related policies are developed and implemented to locate missing persons with dementia. Effective implementation of alert systems relies on cross-sector collaboration, clear and consistent policy, user-centered design, sustained funding, dementia-specific training and public education, and continuous evaluation. The framework and recommendations proposed in this dissertation offer practical guidance for policy and practice in alert system implementation to reduce the risks associated with going missing and uphold the safety and dignity of people living with dementia. Sustainability of any alert system implementation relies on rigorous and compelling evaluation of impact.
A Syndemic Approach to Understanding and Exploring COVID-19 Vaccine Hesitancy among University of Waterloo Students, Canada
(University of Waterloo, 2025-08-21) AlShurman, Bara' Abdallah
Vaccine hesitancy (VH) remains a persistent challenge to achieving widespread COVID-19 vaccination. Although initial vaccine rollout efforts witnessed high uptake of the primary series, booster dose uptake has declined, particularly among younger adults. Universities, where primary doses were mandated but boosters remained optional, offer a unique setting to study VH dynamics. These institutions encompass socially connected, information-exposed populations who navigate a developmental stage for forming health-related decisions. Recent scholarship has conceptualized VH not only as an individual behavioral issue but as a social phenomenon that spreads across communities, often amplified by misinformation and peer influence. Given that COVID-19 has been described as a biological pandemic and VH as a social epidemic, their co-occurrence may constitute a syndemic, where each amplifies the effects of the other and suppresses vaccine uptake. As booster coverage continues to decline, applying a syndemic lens to VH among students is essential for guiding future vaccination strategies. This dissertation addresses critical gaps in COVID-19 VH research. First, existing scales offered limited constructs that did not capture the multidimensional nature of VH or were not validated for booster-specific attitudes. Additionally, most prior studies assessed VH at a single vaccine stage, overlooking how attitudes evolve from mandatory primary series to voluntary booster decisions. Moreover, while syndemic theory has gained traction conceptually, its empirical application in the context of VH remains limited, with most studies relying on theoretical or qualitative descriptions rather than quantitative tests of interaction effects. To address these gaps, the objectives of this thesis were to (1) validate a COVID-19 Vaccine Hesitancy Scale (CVHS) to measure VH for COVID-19 primary and booster doses among students at the University of Waterloo (UW) in Canada, (2) estimate COVID-19 VH prevalence and identify key factors driving VH across primary and booster doses, and (3) examine the syndemic interaction between VH and COVID-19-related factors (e.g., COVID-19 diagnosis, COVID-19 hospitalization, adherence to public health guidelines, and beliefs in conspiracy theories) in shaping booster uptake. This dissertation is based on a cross-sectional survey of 4,453 students at UW, Canada, conducted in 2024. The first study adapted the CVHS to measure VH toward both primary and booster COVID-19 doses among university students. Exploratory and confirmatory factor analyses, along with reliability and validity tests, were conducted to assess the underlying factor structure and evaluate model fit. Results indicated a three-factor structure across both scales, with high internal consistency and excellent model fit. The scale demonstrated adequate convergent, discriminant, and criterion validity. VH was significantly higher for booster doses (33.4%) than primary doses (19.3%) with more students delaying (32.1%) or refusing boosters (29.3%) than delaying (11.5%) or refusing (6.2%) primary doses. The second study examined how VH shifted from primary to booster doses and what factors contributed to this VH change using Generalized Estimating Equations. Results showed a marked increase in VH, with mean scores rising from 7.3 (SD = 7.1) for primary doses to 10.9 (SD = 8.1) for boosters. VH prevalence doubled from 17% to 33.4%. The largest VH increases were seen among women and younger students. Students with low perceived risk, negative booster perceptions, low trust in government recommendations, and lack of prior flu or meningococcal vaccination showed greater VH change. Conversely, students with no religious affiliation and those less influenced by vaccine mandates showed smaller VH shifts. The third study tested the central syndemic hypothesis and investigated whether changes in VH interacted with COVID-19-related experiences to influence booster dose uptake. Logistic regression models were used to estimate main and interaction effects on booster uptake. Increased VH was associated with a 23% reduction in the likelihood of receiving a booster. Younger age, no COVID-19 hospitalization, absence of flu vaccination, non-compliance with public health guidelines, and belief in conspiracy theories predicted lower booster uptake. Interaction analyses revealed that the negative effect of VH on booster uptake was stronger among students who complied with public health guidelines and those who rejected conspiracy beliefs. Interestingly, among participants uncertain about their hospitalization status, increased VH was associated with higher booster uptake. This dissertation contributes new evidence that VH is dynamic and context-dependent, evolving significantly between vaccine phases. Findings underscore that the effect of VH is magnified when interacted with COVID-19 experiences such as pandemic fatigue, stigma, and conspiracy beliefs, together constituting a syndemic. This indicates the presence of a “latent hesitancy” among individuals who may outwardly engage in preventive behaviors but internally remain skeptical or fatigued by ongoing vaccine messaging. As such, vaccine mandates, broad awareness campaigns, or generic messaging may be insufficient to address the complex drivers of booster hesitancy. Instead, interventions should be segmented and tailored to specific behavioral profiles, such as compliant-but-hesitant versus disengaged-and-distrustful, rather than treating students as a homogeneous group. Strategies should go beyond one-size-fits-all models and adopt dialogic and supportive approaches, such as vaccine counseling sessions, peer-led discussions, or transparent communication from trusted campus figures. Furthermore, institutions should recognize that VH may shift over time. Ongoing monitoring of VH levels and underlying factors through rapid surveys can support targeted public health interventions.
Aging Under Pressure: Stress, Inflammation, and Cognitive Change in Immigrant and Non-Immigrant Canadians
(University of Waterloo, 2025-08-20) Shorey, Carrie
Background Cognitive impairment and its risk factors are a growing global concern, particularly among understudied populations such as immigrants. Physical health, psychosocial, and mental health stressors (“stress”) are all linked to poorer cognitive function. While immigrants are more likely than non-immigrants to experience adverse effects of stress, likely due to greater exposure to stressors, they may also experience unique psychosocial and mental health stressors. At the same time, they may benefit from physical health protective factors such as the “healthy immigrant effect”. However, whether their distinct stress profile increases their vulnerability to cognitive impairment remains unclear and was therefore the key focus of this dissertation. Further, because stress can elevate systemic inflammation, this research examined whether inflammation mediated the association between stress and cognitive function. The role of sex in this association was also explored, as immigrant women often experience higher levels of stress, which may amplify inflammatory responses and contribute to worse cognitive outcomes compared to immigrant men and non-immigrants. Methods All studies used data from the Canadian Longitudinal Study on Aging’s (CLSA) Comprehensive cohort, a prospective, population-based study of Canadians aged 45-85 at baseline (n = 30,097, including 5,449 immigrants). Structural equation models examined the association between baseline physical health (measured by physical health conditions), psychosocial (measured by barriers to social activities, financial need, and housing problems), and mental health (measured by psychological distress) stressors with executive function and memory at baseline and three-year follow-up. Analyses were stratified by immigrant status and sex, with inflammation (measured by C-reactive protein; CRP) tested as a potential mediator. Models were adjusted for age, education, and congruence between the participant’s first language learned and the language of the cognitive testing. Results Study 1: Physical health stress. Negative associations of physical health conditions with executive function and episodic memory were more consistent among non-immigrants than immigrants. In non-immigrants, significant negative associations were observed at both baseline and follow-up, whereas among immigrants, effects varied by sex. While immigrant women showed no association between physical health conditions and baseline episodic memory, they exhibited significant associations with all other cognitive outcomes. In contrast, for immigrant men, physical health conditions were only associated with baseline episodic memory and not with any other cognitive outcomes. These findings suggest that stress related to physical health conditions had a more limited role in cognitive outcomes for immigrant men compared to immigrant women and non-immigrant women and men. Although CRP significantly mediated some associations, the effects were clinically negligible. Study 2: Psychosocial stress. Associations of psychosocial stress with executive function and episodic memory were observed in both immigrants and non-immigrants. However, immigrant women were the least likely to show significant associations between psychosocial stress and cognitive outcomes, while immigrant men were the most likely, showing stronger associations than immigrant women and non-immigrant women and men across all of the cognitive domains and time points. This pattern highlights the disproportionate impact of psychosocial stress on cognitive outcomes among immigrant men. While there were statistically significant mediations by CRP, they were clinically negligible. Study 3: Mental health stress. Negative associations of psychological distress with executive function and episodic memory were observed in both immigrants and non-immigrants. However, immigrant women and men experienced more pronounced associations between psychological distress and baseline executive function than non-immigrant women and men. Notably, immigrant men also showed a strong association with baseline episodic memory, further emphasizing their susceptibility to the effects of mental health stress on cognition. While there were statistically significant mediations by CRP, they were clinically negligible. Contribution To our knowledge, no previous studies globally have measured the complex effects of stress and inflammation on cognition in aging immigrants. The findings align with the “healthy immigrant effect” as, despite physical health conditions being generally similar between immigrants and non-immigrants, their impact on cognition was greater among non-immigrants. This suggests that while stress related to physical health conditions was less strongly linked to cognition in immigrants, psychosocial and mental health stress may be more strongly associated with cognitive outcomes in this group. Notably, immigrant men were the most likely to show significant negative associations of psychosocial and mental health stressors with cognition, highlighting their particular vulnerability and a potential area for targeted intervention. While stress-related cognitive vulnerabilities were evident across all of the groups, the strength and consistency of these associations varied, suggesting that certain subgroups may be more vulnerable to stress and may benefit from targeted support. Although CRP significantly mediated some associations across all categories of stressors, the effects were consistently negligible, suggesting that systemic inflammation, as measured by baseline CRP, was not the primary mechanism linking chronic stress to cognition in these studies. By providing much-needed data on a diverse immigrant population—unlike much of the existing literature, which focuses on more homogeneous groups—these studies contribute to a broader global understanding of how stress impacts cognitive function in aging adults, with implications for public health and policy across different immigration contexts.
An Exploration of Quality-of-Life Surveys and Indicators in Long-Term Care Homes
(University of Waterloo, 2025-08-18) Nova, Amanda
Introduction: Residential long-term care (LTC) homes are tasked with protecting residents’ health and wellbeing as well as their quality of life. However, insufficient focus on action-oriented quality-of-life monitoring may limit the scope of quality assurance activities that LTC homes engage in. With implementation guidance, subjective quality-of-life indicators could be beneficial for benchmarking, quality comparison, and evidence-informed quality improvement in the LTC sector. This dissertation explored the development, feasibility, and implementation of LTC quality-of-life surveys and indicators with a focus on the interRAI Self-Reported Quality of Life Survey for Long-Term Care Facilities (SQOL-LTCF). Methods: Guided by the Medical Research Council (MRC) Framework for implementing complex interventions, this dissertation included a modified Delphi study, feasibility study, and realist synthesis. First, the modified Delphi study aimed to identify important quality of life indicators through LTC resident and family member focus groups, staff and researcher surveys, and analyses of 2023 data from LTC homes in Flanders, Belgium. Second, the feasibility study used North American SQOL-LTCF data to explore possibilities for risk-adjusting selected quality-of-life indicators. We examined data availability, characteristics, and variability between selected candidate indicators and performed multilevel binary logistic regression modelling to determine whether risk-adjustors would influence LTC home rankings. Third, the realist synthesis examined the implementation of quality of life surveys in LTC homes through a systematic search of academic literature and key stakeholder consultation. Results: The modified Delphi study identified 10 candidate quality of life indicators for the SQOL-LTCF using importance data from 151 research participants and 417 LTC residents. Qualitative and quantitative data determined that, across 11 quality of life domains, respect and safety tend to be relatively more important than personal relationships with other residents and staff. In the feasibility study, an analysis of data from 16,141 LTC residents across 236 LTC homes demonstrated the feasibility of between-home quality comparisons using the SQOL-LTCF. The study also suggested that risk-adjustment based on age or self-rated health could support quality-of-life benchmarking between North American LTC homes. Finally, the realist synthesis found that supportive and empowering contexts, trustworthy data sources, and meaningful stakeholder engagement can support the implementation of quality of life surveys for care planning, quality improvement, and information sharing. Conclusion: Quality of life surveys and indicators show promise for promoting quality assurance activities such as quality monitoring, benchmarking, and comparison. However, individual, organizational, and regulatory contexts can serve as barriers or facilitators. Social desirability biases, workforce shortages, instrument development considerations, privacy-related barriers to data collection, and the quality of interorganizational relationships each have important implications for quality of life monitoring. Ethics: This study has received ethics clearance through the University of Waterloo Research Ethics Board (#45825, #45826) and Social and Societal Ethics Committee of KU Leuven (G-2023-6931-R3(MAR)).

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