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.

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Perceived Differential Parenting and Childhood Physical-Mental Multimorbidity
(University of Waterloo, 2025-01-02) Barclay, Christopher
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
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
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.
A psychometric evaluation and application of a measure of food literacy among young adults
(University of Waterloo, 2024-11-11) Holmes, Martin
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
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
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
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
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.
Understanding Perspectives on Care Manager Competencies: A Multiple-Method Needs Assessment
(University of Waterloo, 2024-09-18) Romano, Leonardo
Background: Home-based primary care may be well situated as an alternative to conventional episodic primary care for chronically ill older adults, potentially delaying and reducing long-term care admissions while improving satisfaction with care and quality of life. Care management, which seeks to assist patients and their support systems in managing their illnesses, could play a key role in providing home-based primary care. However, little is known about the attributes and competencies a care manager should have when working in home-based primary care. Objectives: To identify necessary competencies for care managers who work with older adults, verify competencies in a home-based setting, and gain a deeper understanding of why the competencies are important. Methods: A scoping review following Arksey and O’Malley’s framework was conducted. A search string encompassing care integration, care management, and clinical competence was used to find academic literature on PubMed, CINAHL, and Scopus. The academic search string was adapted to custom Google searches and targeted website searches to identify grey literature. Extracted competencies were organized into similar groups. The sixth step of Arksey and O’Malley’s framework, consultation, was conducted using a quantitative survey to verify the literature review’s findings, and qualitative interviews to gain a greater understanding. The survey used the competencies uncovered in the scoping review and asked care managers and healthcare providers to rank the importance of competency groups with respect to one another, and rate the importance of individual competencies from -3 to +3, with -3 being very unimportant and +3 being very important, in a home-based setting. Results: The literature review identified 125 competencies from 65 academic articles and pieces of grey literature. These were categorized into 13 groups in three audience-facing facets. A total of 20 survey participants rated competencies and ranked competency groups, the averages of which were used to ascertain the degree to which they are important for care managers. The highest-rated competencies were patient-facing relationship and rapport building (2.90) and patient-facing confidentiality (2.90); the highest-ranked competency group was patient care management (2.80). Cronbach’s alpha for the survey was 0.93. A follow-up interview was conducted which provided further endorsement and nuance for some competencies, as well as a test for the feasibility of further qualitative investigation. Discussion and Conclusion: The findings provide support for the importance of competencies for care managers who work in home-based settings with older adults. The review identified competencies beyond those suggested by professional organizations; these included personality traits and caregiver support and communication. Further contextualization is needed to gain a deeper understanding of why the identified competencies are important. Practitioners should be aware of the breadth of competencies a care manager may need to possess when working in home-based settings with older adults and should prioritize training according to their importance.
Using Latent Class Analysis to Create Allostatic Load Profiles to Investigate the Effects of Occupational and Perceived Stress in Firefighters
(University of Waterloo, 2024-09-17) Elliott, Madelyn
Background: Allostatic load is a construct used to assess the sum of the effects of physiological stress across multiple body systems over time. Allostatic load is typically measured using the allostatic load index (ALI); however, this measure does not fully capture the multivariate nature of allostatic load. Using allostatic load profiles as opposed to the commonly used ALI, we hope to explore the multivariate nature of allostatic load and understand its association with perceived stress, since the existing literature exploring the association between perceived and physiological stress is inconclusive. Objectives: The objectives of this thesis are to 1) develop allostatic load profiles using latent class analysis of both study-created and clinical-based thresholds for biomarkers of stress; 2) examine the association between allostatic load profiles and perceived stress in firefighters; 3) assess whether study-based or clinical-based thresholds are more suitable when measuring stress in the firefighters in question. Methods: Using available biomarker data from a sample of 57 male firefighters in Waterloo Fire Rescue, we developed allostatic load profiles using latent class analysis. Biomarkers included systolic blood pressure (SBP), diastolic blood pressure (DBP), hemoglobin A1c (HbA1c), low-density lipoprotein (LDL), high-density lipoprotein (HDL), heart rate variability (HRV), cortisol, waist to hip ratio (WHR) and body mass index (BMI). We then employed logistic regression to assess the association between allostatic load profiles and perceived stress in these firefighters. Results: Our results demonstrated that the use of allostatic load profiles (ALPs), created with study-based thresholds, showed how different biomarkers contribute to elevated or non-elevated physiological stress profiles. In regression models of ALP on Perceived Stress Scale (PSS-10) scores, we saw a consistent positive association such that an increase of 1 unit in PSS-10 score increased the odds of being in the elevated ALP group anywhere between 13.6% (OR = 1.136, 95% C.I. = 1.012, 1.299) in a model with PSS-10 only to 19.2% (OR = 1.192, 95% C.I. = 1.039, 1.400) in a model with PSS-10, length of service (LOS), and the following behavioural confounders: smoking, sleep hours, exercise and alcohol intake frequency. Conclusions: Allostatic load profiles captured the multivariate nature of allostatic load and demonstrated a significant association with the PSS-10, whereas ALI was unable to significantly demonstrate a relationship with perceived stress. The results of this thesis also demonstrated the need for using study-based or study-specific thresholds when examining unique populations with different fitness levels than the general population. Further research can benefit from the use of allostatic load profiles in conjunction with study-based thresholds to accurately and completely address the needs of persons working in high-stress, dangerous occupations.
Assessing the Use of Research Techniques for Supporting the Engagement of People Living with Dementia in Research
(University of Waterloo, 2024-09-04) Conway, Emma
People with dementia often experience challenges communicating their experiences, which can impact their ability to participate in research. Adapted or modified research methods are needed to better promote the accessibility of research for people with dementia in support of their rights to participate. This manuscript-based thesis employed three studies to examine the use of adapted or modified research methods to engage people with dementia in research and evaluate the use of two techniques for their impact on the engagement of people with dementia in research and on the data produced. First, a scoping review of the current literature was conducted to identify studies that used adapted or modified research methods with people with dementia with the aim of understanding the extent of use of adapted methods with people with dementia in qualitative research. The review identified adapted methods used and examined how impacts on engagement as it relates to meeting accessibility needs were investigated. Two primary qualitative research studies were also conducted to examine two projective interviewing techniques, verbally-prompted storytelling and photo-prompted storytelling, and how these techniques impact the engagement of people with dementia and the data collected in qualitative interviews. Results from the scoping review suggest that a range of adaptations and modifications are made by researchers to their research projects, but limited evidence exists as to the effectiveness of these adaptations on improving engagement of people with dementia in research. The study of verbally-prompted storytelling techniques suggests these methods deepened reflection of impact of dementia on self and others, facilitated conversations when participants experienced challenges recalling a personal example, and enabled conversations about emotional topics. Additionally, the study of the photo-prompted storytelling technique suggests that participants tended to demonstrate deeper reflection of their own and other’s experiences and that the photo-prompted storytelling technique helped overcome challenges with direct questioning and recall. As well, there was a statistically significant difference in observed engagement when participants were interviewed using photo-prompted storytelling techniques but not the verbally-prompted story telling technique. This dissertation contributes to the understanding of adapted and modified methods to engage people with dementia in research and provides preliminary evaluation of projective interviewing techniques for improving the engagement of people with dementia in qualitative research, and how such techniques impact data collected. Improving accessible research opportunities for people with dementia to share their experiences is essential for recognizing the human rights of people with dementia to have equal opportunities to participate. Future research should continue to explore and extend the application of these techniques with particular focus on the impact of the specific prompts used.
The Use of Vaping Products in Attempts to Stop Smoking: Trends Over Time and Possible Substitution for Other Smoking Cessation Aids in Canada, the United States, England, and Australia
(University of Waterloo, 2024-09-04) D'Mello, Kimberly
Background: E-cigarettes are a popular method of smoking cessation assistance. However, few studies have examined whether e-cigarettes serve as a substitute for other effective smoking cessation assistance, including how population-level changes in the use of e-cigarettes for smoking cessation compare to changes in the use of nicotine replacement therapy (NRT), prescription pharmacological therapies, and other smoking cessation methods. Objectives: To examine changes in the types of cessation assistance used by people trying to quit smoking over time, including: 1) the use of e-cigarettes in a quit attempt and 2) the use of other effective methods of cessation assistance. Methods: The study protocol has been preregistered (https://osf.io/jpnqc). Data are from the 2016, 2018, and 2020 Waves of the ITC Four Country Smoking and Vaping Survey. Respondents were recruited by commercial panel firms in each country who were ≥ 18 years of age and, who currently smoke, recently quit smoking, and/or currently vape. Analyses examined the use of cessation assistance among the 14,551 observations from participants with an attempt to quit smoking in the past 12-months since survey date (CA=4,880; US=2,917; EN= 4,846; AU=1,898). Repeat cross-sectional analyses were conducted using generalized estimating equations stratified by country. Results: Across all countries, e-cigarettes (29.9%) and nicotine replacement therapies (NRT; 29.8%) were the most commonly reported categories of cessation assistance used in a previous quit attempt, followed by self–help services (17.8%), and prescription pharmacological therapies (12.6%). Overall, more than half (59.4%) of respondents used ‘any’ form of effective cessation assistance (including e-cigarettes). E-cigarette use increased in Australia from 2016 (11.1%) to 2020 (25.1%; OR=2.29, 95% CI=1.37-3.82, p=.002). In England, e-cigarette use increased from 2016 (37.1%) to 2018 (46.7%; OR=1.40, 95% CI=1.13-1.73, p=.002), and had no changes over time in Canada or the US. Use of other effective cessation methods (with and without e-cigarettes) had no changes over time in all countries, excluding Canada. In Canada, use of ‘any’ form of effective cessation assistance (including e-cigarettes) decreased from 2016 (64.0%) to 2020 (58.9%; OR=0.75, 95% CI=0.61-0.93, p=.010). Conclusion: Overall, there were strikingly similar rates of effective cessation assistance used across all four countries, despite differences in e-cigarette use and regulatory environments. While e-cigarettes are a popular choice of cessation method, there was little evidence that trends in use of e-cigarettes contributed to changes in the use of ‘any’ effective form of cessation assistance. The extent of ‘substitution’ between individual quit methods at the population-level was not directly assessed in this study; however, there was some evidence consistent with substitution for e-cigarettes and use of prescription therapies such that, the use of prescription therapies increased in England as the use of e-cigarettes as a quit method decreased, with the inverse trend in Australia; and little to no changes in the US and Canada.
Evaluating Synthetic Data as a Proxy for Real Clinical Data in Machine Learning Models: A Comparative Study on Postpartum Hemorrhage Prediction
(University of Waterloo, 2024-08-30) Sharma, Kam
Introduction: This thesis investigates the use of synthetic data as a proxy for real clinical data in predictive modeling, focusing on postpartum hemorrhage (PPH). Synthetic data offers a solution to privacy concerns by providing data that mimics real patient data without compromising patient information. The goal is to develop and validate predictive models for PPH using synthetic data and comparing it to the real data, thereby assessing the feasibility and effectiveness of synthetic data in clinical settings. Methods: Synthetic data was generated using Generative Adversarial Networks (GANs) from MDClone to replicate the statistical properties of real clinical data from Ottawa Hospital. The data underwent a thorough cleaning and preparation process, followed by feature selection. Machine learning and statistical models, including logistic regression, decision trees, random forests, and support vector machines, were developed and trained on the synthetic data and then the pipeline was run on the real data at Ottawa Hospital. Model performance was evaluated using precision, recall, F1-score, accuracy, and Area Under the Curve (AUC) of the Receiver Operating Characteristic (ROC) curve. Results: The synthetic data closely mirrored the real data in statistical properties, with low Hellinger distances for most variables. Machine learning models trained on synthetic data demonstrated high performance, with comparable results to those trained on real data. Key predictors for PPH were determined which included the administration of certain medication and clinical parameters. The comparative analysis showed minimal discrepancies between model outputs from synthetic and real data, validating the use of synthetic data for predictive modeling. Discussion: The findings indicate that synthetic data can effectively be used to develop predictive models for PPH, and addressing data accessibility. The study highlights the potential of synthetic data to enhance predictive modeling in healthcare, providing a viable alternative to real data without compromising accuracy. The integration of synthetic data in clinical research can facilitate broader data availability, fostering innovation while adhering to privacy regulations. Conclusion: This research demonstrates the viability of synthetic data in predictive modeling for PPH, with models trained on synthetic data showing high performance comparable to those trained on real data. The study contributes to the theoretical understanding of synthetic data utility and offers practical implications for improving patient outcomes and optimizing healthcare resources. Future research should focus on expanding the use of synthetic data in other clinical areas and further validating its effectiveness in diverse healthcare settings.
Food insecurity among adults and adolescents in Australia, Canada, Chile, Mexico, the United Kingdom, and the United States before and during the Coronavirus Disease 2019 Pandemic
(University of Waterloo, 2024-08-30) Pepetone, Alexandra
Background: Household food insecurity is a major public health concern with negative consequences for health and well-being among adults and adolescents. During the Coronavirus disease 2019 (COVID-19) pandemic, shocks and stabilizers may have affected the prevalence and severity of household food insecurity overall and among subgroups of the population. For example, restrictions to reduce the spread of COVID-19 led to loss of employment, potentially increasing risk of food insecurity, whereas policies such as income supplementation for those who lost employment may have had a stabilizing effect. Comparing changes in household food insecurity across multiple countries over time can shed light into how packages of economic and social policy responses implemented or revised by national level governments during the pandemic may have influenced household food insecurity, providing insights into strategies to ameliorate household food insecurity, including in times of crisis. Objectives: The objectives of this thesis were to 1) characterize changes, or lack thereof, in the prevalence and severity of food insecurity among adults and adolescents in Australia, Canada, Chile, Mexico, the United Kingdom, and the United States from before (2019) to during (2020) the pandemic (Chapter 5); 2) examine national level government economic and social policy responses implemented or revised in these countries to, in part, mitigate the impacts of the COVID-19 pandemic and related safety measures (Chapter 6); and 3) determine whether economic and social policy responses appeared to mitigate anticipated increases in food insecurity during the COVID-19 (Chapter 7). The countries of interest were identified based on the similarity in the languages spoken, food environments, and culture among other characteristics. Methods and results: Three inter-related studies addressed the thesis objectives, with two of the studies integrating consultation with a collaborative working group to facilitate the relevance and applicability of study findings by considering country-specific contexts. Two studies drawing upon the International Food Policy Study considered food insecurity data reported by adults aged 18 to 100 years and directly by adolescents aged 10 to 17 years, enabling comparison in trends among the two population subgroups over time. Among adults, food insecurity was measured using the 18-item Household Food Security Survey Module, enabling categorization of the households in which participants lived as food secure or food insecure over the past 12 months. Among adolescents, the 10-item Child Food Insecurity Experiences Scale was used, enabling consideration of the number of food insecurity experiences (i.e., no, few, many, or several) they had over the past 12 months. The first study (Chapter 5) drew upon repeat annual cross-sectional data from adults (n = 63,278) and adolescents (n = 23,107) to examine changes in food insecurity prevalence and severity from before (2019) to during (2020) the COVID-19 pandemic in the countries of interest. Based on adjusted binary and multinomial logistic regression models, adults in Australia (adjusted odds ratio (AOR): 0.81; 95% CI: 0.72-0.92) and Canada (AOR: 0.87; 95% CI: 0.77-0.99) were less likely to live in food-insecure households during (2020) relative to before (2019) the pandemic. There was little indication of changes in the odds of adults living in food-insecure households in the United Kingdom (AOR: 0.90; 95% CI: 0.79-1.02) and the United States (AOR: 1.05; 95% CI: 0.93-1.19) in 2020 relative to 2019, while in Mexico, adults were more likely (AOR: 1.15; 95% CI: 1.02-1.31) to live in food-insecure households in 2020. Findings related to changes in the severity of food insecurity were similar. Adolescents in Mexico were more likely (AOR: 1.43; 95% CI: 1.19-1.71) to report experiencing food insecurity in 2020 compared to 2019. In Australia (adjusted relative risk ratio (ARRR): 2.24; 95% CI: 1.65-3.02) and the United States (ARRR: 1.39; 95% CI: 1.04-1.86), adolescents had a higher relative risk ratio of many compared to no experiences of food insecurity in 2020 compared to 2019. No differences in the prevalence or number of experiences of food insecurity among adolescents were observed in other countries. In the second study (Chapter 6), packages of economic and social policy responses to, in part, mitigate the impacts of the pandemic and safety measures to limit spread of the virus in the countries of interest were characterized. Potentially relevant policy responses implemented or revised by national governments between January 2020 and December 2022 were identified using eight policy response trackers. A theory of change articulating the hypothesized influence of different types of policy responses on household food insecurity guided the inclusion criteria. Two rounds of screening were conducted to identify the final set of 142 relevant economic and social policy responses. Hypotheses about how policy packages influenced household food insecurity in 2021 and 2022 were developed based on observed changes in household food insecurity from 2019 to 2020 and broader contextual events. Consideration of the influence of policies on food insecurity in 2021 and 2022 integrated evidence from other sources. Financial-based policy responses (e.g., unemployment protection) were emphasized in Australia, Canada, and the United Kingdom. In Chile, Mexico, and the United States, there was a more equal distribution of financial-based and resource-based (e.g., food assistance) policy responses. Across most countries and years, policy packages provided long periods of coverage (six months or more). Mexico was an exception in 2021 with a mix of policy responses that had short- and long-term coverage. The third study (Chapter 7) drew upon repeat cross-sectional data from 104,418 adults and 44,759 adolescents from 2018 (adults only), 2019, 2020, 2021, and 2022 to determine whether economic and social policy responses mitigated anticipated increases in food insecurity among adults and adolescents during the COVID-19 pandemic. Three lines of inquiry were used to realize this objective. First, year-to-year changes in food insecurity among adults and adolescents and in the known determinants (e.g., difficulty making ends meet) and consequences (e.g., poor quality diets) of food insecurity were compared. Alignment in changes would instill confidence that the nature of food insecurity did not change during the pandemic and set the foundation for the subsequent two lines of inquiry. Second, among adults living in households, the predicted prevalence of food insecurity in 2020, 2021, and 2022 had the pandemic not occurred was estimated (this analysis was not conducted for adolescents given the lack of data for 2018). Hypothesized changes in food insecurity among adults living in households for each country by year given that the pandemic occurred and considering broader contextual events (e.g., global inflation, Brexit in the United Kingdom) were developed to guide assessment of whether economic and social policy responses mitigated anticipated increases in food insecurity. Observing that the observed proportion of adults in food-insecure households was lower or did not differ from the predicted proportion would suggest that economic and social policy responses mitigated anticipated increases in food insecurity. Third, adjusted multinomial or binary logistic regression models with interactions for the survey year and selected characteristics that indicate high risk of experiencing food insecurity (e.g., households with children) assessed changes in the odds or relative risk ratio of food insecurity among adults living in households and adolescents during (2020 to 2022) relative to before (2019) the COVID-19 pandemic among the subgroups selected. Subgroups with selected characteristics were anticipated to be more likely to experience food insecurity during the pandemic. If this finding was not observed, it would suggest that economic and social policy responses mitigated anticipated increases in food insecurity among those at high risk during the pandemic. Alignment between changes in food insecurity among adults living in households and adolescents and its known determinants and consequences ranged across countries and over time. The variation in alignment was likely due to the range of factors that could influence food insecurity and the unlikelihood that a one percent change in the proportion of food insecurity would equate to a one percent change in the singular category examined for each determinant and consequence. The observed proportions of food insecurity among adults living in households were lower than predicted had the pandemic not occurred in Australia, Canada, and the United States at various time points, suggesting that policy responses to address pandemic-related disruptions mitigated increases in food insecurity that were otherwise anticipated to due to shocks related to COVID-19 safety measures. Subgroups that were anticipated to be more likely to experience food insecurity during (2020 to 2022) relative to before (2019) the COVID-19 pandemic largely did not, with indication that some subgroups were better protected by policies introduced during the pandemic compared to beforehand. Conclusions: Although some increases in food insecurity among adults were observed through the pandemic in the countries examined, it appears that economic and social policies introduced by national governments mitigated otherwise large, anticipated increases due to loss of income and other shocks to households. The lack of increases in the proportions of adolescents experiencing food insecurity in most countries reinforces the notion that policy packages influenced food insecurity during the pandemic. Nonetheless, household food insecurity remains prevalent and increased in later years, likely due to the expiration of policy responses, inflation, and other events globally. Though long-term economic and social policies to address household food insecurity are lacking in the countries examined, this work indicates it is possible for governments to ameliorate this serious public health problem using policy levers. Packages of policy responses that focused on financial-based support and/or scaled up existing policy responses mitigated anticipated increases in food insecurity among adults in 2020. Policy packages also appear to have contributed to the observed prevalence of food insecurity among adults living in households being the same or lower than the predicted prevalence through the pandemic. These findings are salient as the world works to achieve the 17 Sustainable Development Goals by 2030 against the backdrop of ongoing crises anticipated to sharply increase risk of household food insecurity, including the climate emergency and conflicts.
Improving Nutrition Risk Screening for Community-Dwelling Frail Older Adults
(University of Waterloo, 2024-08-29) Jackson, Meagan
Background: As Canada's population continues to age, it is essential to screen for nutrition risk in frail older adults to support older adults to benefit from services and care that can improve their nutrition and prevent outcomes of nutrition risk, such as frailty. Frailty is defined as "an age-related syndrome of physiological decline, characterized by marked vulnerability to adverse health outcomes" (Walston et al., 2022). Over time, insufficient protein and energy intake may increase the risk of malnutrition (Hoogendijk et al., 2019) and may lead to weight loss in an older population, which is an indicator of frailty (Cederholm et al., 2019; Fried et al., 2001: Wei et al., 2018). The Seniors in the Community Risk Evaluation for Eating and Nutrition (SCREEN)-14 is a 17-item questionnaire created to measure nutrition risk in older adults aged 50+ (Keller et al., 2005). As SCREEN was created before frailty became a relevant concept in clinical care, refinements to SCREEN-14 may be needed to specifically target frail older adults. Further, to promote use of nutrition screening tools in practice, they need to be as brief as possible. SCREEN-8 was developed using a mixed method of classical test theory and expert opinion to meet this need. However, it is not known if this is the best short version of the tool, specifically considering frail older adults. Objectives: The objectives of this thesis were to: (1) use expert opinion to determine the minimum set of SCREEN-14 questions needed to identify nutrition risk in potentially frail older adults (i.e., content validity), and if any new questions are required (Chapter 4) (2) use Item Response Theory (IRT) to also identify a minimum data set that can differentiate those most likely to be at risk, and specifically within the oldest age groups (proxy for frailty) (Chapter 5), and (3) evaluate the differences and overlap in these tools as compared to SCREEN-8. (Chapter 5). Two discrete studies will be completed to address these objectives. Methods and results: The first study (Chapter 4) uses a Delphi technique which gathers expert opinion and builds consensus on an issue by way of anonymous surveys. Forty-six experts in the field who have used SCREEN in the past and had contacted the originator were invited to participate in a two-round Delphi process. Eighteen experts participated throughout the two rounds. They were asked to rate (first round survey) and confirm (second round survey) the importance of current SCREEN-14 items for the inclusion in a minimum set that specifically could identify risk in those who are frail. Additional questions were asked on expansion of items (round one) and consensus on inclusion of new items (round two). The experts concluded that eight current SCREEN questions should be included in the final set with no new questions added. The second study (Chapter 5) addresses objectives two and three in a secondary data analysis of the Nutri-eSCREEN dataset. Nutri-eSCREEN contained SCREEN-14 in an online platform as well as self-reported sex, age, and geographic location. After cleaning and applying the exclusion criteria there were n=20,093 participants in the dataset used in the analyses. To address objective two, psychometric models, specifically a Graded Response Model (GRM) was conducted to identify a draft minimum SCREEN (i.e., what items discriminate risk) using the whole sample as well as only participants 75+years (n=2,749) to serve as a proxy for frailty. From both samples eight different questions (six of them overlapping) were identified using the item parameter estimates and consideration on coverage of the concept of nutrition risk. The IRT 75+ version was decided to be a better tool and used in subsequent analyses. Using demographic variables, a bivariate analysis was also completed to determine the statistical differences among SCREEN-14 questions by sex and age groups to demonstrate construct validity of the abbreviated IRT version. Variations of SCREEN (SCREEN-8 and SCREEN resulting from the Delphi) were created for comparison to this IRT version resulting from the GRM analysis to address objective three. SCREEN-8 identified the highest proportion at risk (42.1%) and the SCREEN-IRT the least (27.7%). The overlap of all three versions identifying participants to be at risk was 77.4%. Finally, model fit statistics among the three brief versions were calculated with SCREEN-8 and SCREEN-IRT found to be better tools than SCREEN-Frail. Conclusion: As the population is rapidly aging, easy to use and brief tools that target nutrition risk identification to those most in need of further evaluation are required. These studies helped to identify two separate potential versions of SCREEN through different methods. The different versions both contained eight questions as does SCREEN-8. The conclusion is that although these two new versions were created via consensus and IRT methods they do not appear to be superior to SCREEN-8 with respect to, brevity, model fit, and identification of prevalence of risk. Future work should further test and validate these versions for comparison to SCREEN-8.
Exploring the Journeys of People Accessing Abortion Care in Ontario, Canada
(University of Waterloo, 2024-08-23) Slofstra, Kathleen Nicole
Background: Abortion has been a contentious socio-political issue throughout Canada’s history. Despite the decriminalization of abortion in 1988 and the approval of medication abortion in 2015, challenges to accessing abortion in Ontario still exist. There is a dearth of research on people’s experiences of accessing abortion, especially in an Ontario context. Research Questions: What are the experiences of people accessing and receiving an abortion in Ontario? When reflecting on their abortion care journeys, how do people who have obtained an abortion perceive their care encounters? How can the provision of abortion care be improved in the Ontario health care system? Methods: This research project used a qualitative research design, drawing on 16 in-depth, semi-structured narrative interviews from racially and gender diverse participants across Ontario. Participants were recruited through social media accounts of reproductive care organizations. Individuals were eligible to participate in the study if they had received a procedural and/or medication abortion in Ontario in the last 3 years (2020-2023). Interviews were conducted virtually or over the telephone and lasted 1-1.5 hours. This study also employed a novel technique of healthcare journey mapping during interviews to visually depict key healthcare encounters. Narrative-thematic analysis was used to capture themes from participants’ stories. Findings: Five individuals’ stories and abortion care journey maps are highlighted, demonstrating multiple routes to accessing care and the differential complexity of navigating care. In the next chapter, participants’ accounts are structured into four main themes by story plot element. Most participants encountered difficulties and/or stress accessing care, which posed as the first complicating action in their journeys. The next complicating action stemmed from their interactions with abortion care professionals during diagnostics and assessment of the pregnancy. A range of interactions with care professionals were narrated, fluctuating between services being perceived as restrictive, rushed, and shame-inducing to caring, connective, and, non-judgemental. All participants received at least one abortion, categorized as the plot climax of their story. Participants often found the process of receiving an abortion emotional and/or physically painful. Lastly, the degree of “resolution” of participants’ stories was impacted by the quality of post-abortion care they received for their ongoing physical or emotional needs. Conclusions: This study is one of the first to blend narrative inquiry with the novel technique of healthcare journey mapping to people’s experiences of abortion care, identifying the gaps in services to provide clients with non-judgemental care. By highlighting a few abortion care maps and stories, it suggests that space needs to be carved out in the healthcare system to provide individualized care sensitive to clients’ emotional, physical, and spiritual needs. It makes several recommendations as to how abortion practice and policy can be improved to be more trauma-informed, abortion-focused, and client-centered.
Examining extreme weather event preparedness, response, and recovery among community health workers in Negros Oriental, Philippines: A qualitative study
(University of Waterloo, 2024-08-23) Beggs, Bridget Elizabeth
Background: The Philippines remains one of the most vulnerable countries to extreme weather events, which will continue to increase in frequency and severity due to the climate crisis. To urgently address this challenge, community-based strategies have been emphasized as a key component of climate resilient health systems. Community health workers (CHWs) often act as an important resource to deliver health-related support and care in resource-constrained settings and may strengthen community resilience amid disasters. However, there is a need to consider how individual-context and program-specific factors may impact the ability of CHWs to support their communities during extreme weather event preparedness, response, and recovery. This study aimed to explore the experiences of CHWs during extreme weather events to understand how their positionality, existing responsibilities, and perceived capacity shaped their ability to support communities amid extreme weather events. Methods: This study was conducted in partnership with International Care Ministries (ICM), which is a Philippines-based non-governmental organization. ICM implements the Flourish program, where the organization recruits and trains Community Health Champions (CHCs) who operate as CHWs. We conducted 51 semi-structured interviews with CHWs across four municipalities in Negros Oriental, Philippines, in May-June 2023. Recruitment was facilitated through ICM’s pre-existing relationships with CHWs, and data collection and analysis were guided by the disaster risk management framework. All interviews were audio-recorded, transcribed using NVivo software, and thematically analyzed using a hybrid deductive-inductive approach. Results: Participant narratives indicated that experiences with extreme weather events were shaped by both individual and program specific factors, and that CHWs capacity to provide support within their communities varied at each phase of the disaster. Participants also outlined that their level of preparedness for current extreme weather events was impacted by their experiences with past extreme weather events. Further, although most CHWs highlighted that family members were their priority during extreme weather event response, some CHWs also exhibited a willingness to support other community members during response activities. Finally, CHWs were recognized as a source of support during extreme weather event recovery activities, despite sharing socioeconomic and demographic characteristics with other community members and experiencing the disaster in a similar way. Conclusion: Efforts to equip CHWs to support disaster preparedness, response, and recovery need to closely consider both the individual and household-level impacts of extreme weather events that are experienced by CHWs themselves. This study provides insight into how CHWs navigate extreme weather events and underscores the complexities of recognizing CHWs as both health leaders and community members in disaster risk management.
Estimating Incidence of Infectious Diseases in Canada Beyond Surveillance
(University of Waterloo, 2024-08-22) Major, Maria
Introduction Public health surveillance provides valuable information about the epidemiologic trends of infectious diseases but is not designed to provide exact estimates of population-level disease incidence. Case reporting to public health surveillance may be impacted due to a variety of reasons: clinical misdiagnosis, sensitivity and specificity of laboratory testing assays producing false negative results, incomplete case information, failure to report to public health, patient access to healthcare resources, etc. Estimating the true incidence of a disease is particularly important when conducting health economic assessments that evaluate the value of public health interventions. Equally important is to investigate sources of bias in reporting by evaluating differences in case ascertainment by sub-group (age, race, socioeconomic status (SES), gender, etc). The aim of my thesis is to explore alternative methods of estimating incidence of infectious disease of public health importance and where possible, explore potential sources of bias. Study 1: Using Seroprevalence to Estimate Incidence of SARS-CoV-2 in Canada For study 1, a systematic literature review was conducted of SARS-CoV-2 seroprevalence studies in Canada. Disease incidence was estimated from seroprevalence studies, which were then grouped by region and age. Estimated incidence was compared to reported cases by calculating under-ascertainment ratios for each study. Under-ascertainment of cases was highest at the beginning of the pandemic, as access to testing was limited early on. Over time, the under-ascertainment declined, perhaps due to increased access to testing, but may have been confounded by reports of reduced assay sensitivity of thresholds to lower titre levels over time. This work was published in July 2022. Study 2: Estimating Incidence of Lyme Disease in Manitoba using Administrative Data Lyme Disease (LD) is a growing public health threat in Canada due to the impact of environmental factors that favour the expansion of Borrelia burgdorferi-infected ticks (Ixodes scapularis) into Canada. It is widely accepted that LD cases are under reported in Canada, but there are no empirical estimates that quantify true incidence of disease. An algorithm developed by the Center for Disease Control, using administrative healthcare billing codes (ICD-9, ICD-10) for Lyme and prescription data, was clinically validated in several endemic Lyme regions within the US. Access to administrative claims databases is province specific with variation in the types of linked datasets available for research. To ensure compliance with the validated CDC protocol, we needed to have physician billing codes that were specific for LD, hospital discharge abstracts, emergency room visits and antibiotic prescriptions. Our investigation was limited to the eastern Canadian provinces, which is the only habitat for I. scapularis in Canada. Manitoba was selected as an ideal province to conduct this study as it met all the database criteria as well as provided access to public health serology test results for LD, which was not available to the CDC in their study. The algorithm was adapted to the Manitoba database and a protocol was submitted to the Manitoba data custodian for extraction. The primary objective was to to estimate the incidence of LD from 2010-2021, overall, by patient characteristics (e.g., age, sex), and by local residential area. Secondary objectives were to describe the demographic and clinical characteristics of LD cases, and to estimate the clinical stage of patients based upon reported symptoms. The yearly incidence of Lyme cases identified using this method were between 5.1 and 11.0 times higher than those reported to public health surveillance during the study period. There were no clear trends in the under-ascertainment over time. Due to the limitations of using administrative billing data, it was not possible to estimate the clinical stage of identified cases. Study 3: Modeling the impact of elevated LD incidence on population health in Manitoba, Canada LD is an emerging and growing public health threat in Canada due to climate change factors responsible for the rapid expansion of Borrelia burgdorferi-infected ticks (Ixodes scapularis) into densely populated areas. Under-reporting cases to public health and delays early treatment can lead to serious and persistent sequalae. The objective of this study was to construct a cohort LD model to assess the impact of elevated incidence on health-related quality-of-life. The health-related quality-of-life impact of LD in Manitoba over a 10-year period resulted in loss of 13.8 QALYs for the base case (reported incidence) and 73.4 QALYs for the elevated incidence scenario. Our model estimated average direct healthcare costs of $210 for the base case and $1,029 for the elevated incidence scenario, although these costs were taken from an Ontario costing study from reported cases which may underestimate the true cost of treatment of more complicated cases that are untreated during the early clinical stages of LD. Receipt of costing data from Manitoba is expected in June 2024 and will replace the Ontario LD costing estimates. The model was most sensitive to variations in incidence rates and time spent with persistent sequelae, namely arthritis, neurologic sequelae, and Post-treatment Lyme Disease Syndrome (PTLDS). Our model demonstrated that elevated incidence rates that account for under-reporting of LD in Manitoba have a substantial impact on health-related quality-of-life. Conclusion Using two infectious diseases of public health significance, lessons were learned by characterizing their under-ascertainment within the context of access to care, access to testing, and identified equity issues that impact case ascertainment and low disease awareness. The validity of HR-QoL or health economic estimates is questionable in light under-ascertainment. The goal of quantifying under-ascertainment of disease and evaluating the health-related quality-of-life impact provided important insights into burden of disease. Understanding the specific transmission patterns and immune profiles stimulated by exposure were important in designing the studies and interpreting results. Linked administrative datasets are an efficient method of conducting research while preserving patient privacy. Future efforts would benefit from increasing the kind of datasets included in provincial databases, such as inclusion of electronic health records to gather symptom-related data, as well as seroprevalence data from studies conducted by Canada Blood Services or public health. Methods to quantify the level of uncertainty of incidence estimates play an important role in the development and assessment of public health initiatives.
Is diet quality changing over time among adults in Canada? An examination using data from 2018 to 2022
(University of Waterloo, 2024-08-21) Milano, Alyssa
Background: Poor eating patterns have been established as one of the leading risk factors for chronic disease. Numerous efforts have been made to improve the population’s diet quality, yet the last time dietary intake data were collected at the national level was in 2015, and policies are increasingly based on outdated dietary intake data. Existing data suggest poor diet quality in Canada, with indications of disparities by gender identity, age, income, education, and racial-ethnicity identity, but do not enable assessment of whether diet quality is changing over time. Objective: This research was undertaken to examine trends in diet quality from 2018 to 2022 among adults in Canada overall and among groups characterized by sex, age group, perceived income adequacy, educational attainment, and racial-ethnic identity. Methods: Data were drawn from repeat cross-sectional surveys of adults in Canada from the International Food Policy Study (IFPS) (n=13,448). The Healthy Eating Food Index-2019 (HEFI-2019) was applied to 24-hour dietary recall data to assess alignment of intake with the 2019 Canada’s Food Guide healthy food choices recommendations. Mean HEFI-2019 scores, to a maximum of 80 points, were estimated overall and by sex, age, perceived income adequacy, educational attainment, and racial-ethnic identity. A modified approach to the population ratio method was used to estimate scores adjusted for sociodemographic characteristics. Paired t tests assessed changes in mean scores from year to year and from 2018 to 2022, overall and among subgroups. Results: Among the overall sample, there was weak evidence of a decrease in diet quality from 2018 (46.5) to 2019 (44.0) (mean difference -2.46, SE 1.39, P=0.078) and moderate evidence of an increase in mean total HEFI-2019 scores from 2021 (44.7) to 2022 (48.0) (mean difference 3.30, SE 1.57, P=0.035). However, there was no evidence of a meaningful change in diet quality from 2018 to 2022 (mean difference 1.54, SE 1.5, P=0.305). Variations in total scores from year to year were largely attributable to variations in mean vegetables and fruits component scores. Similar patterns in scores across years were evident among some subgroups. Discussion: The findings point to the need for concerted efforts to improve diet quality among adults in Canada. The introduction of the adjusted population ratio allows future studies to better understand diet quality in particular groups, independent of potential confounding factors.
Helpful or harmful? An examination of the relationship between low- and no-calorie sweetener exposure and dietary intake and health
(University of Waterloo, 2024-08-19) Andrade, Lesley
Background: Poor dietary patterns are a major contributor to chronic disease morbidity and mortality globally. Many governments and health authorities have implemented public health initiatives to improve dietary patterns, including by reducing added sugars intake. Replacing added sugars with low- and no-calorie sweeteners is becoming increasingly common, both in the food supply and by individuals. Although low- and no-calorie sweeteners approved for use are considered safe from a toxicological perspective, their long-term impacts on health and chronic disease risk are contested. Objectives: The objectives of this dissertation were to 1) summarize evidence from systematic reviews examining associations between consumption of low- and no-calorie sweeteners and chronic conditions and intermediate risk factors (Chapter 4); 2) develop a standardized approach to classify food codes used in nutrition surveillance in Canada as sources of low- and no-calorie sweeteners (Chapter 5); 3) estimate the proportion of individuals in Canada reporting the consumption of sources of low- and no-calorie sweeteners or tabletop sweeteners on a given day (Chapter 6); 4) characterize the nutrition profiles of sources of low- and no-calorie sweeteners (Chapter 6); and 5) assess diet quality in relation to the probability of consuming low- and no-calorie sweeteners among individuals in Canada (Chapter 7). Methods and results: Chapter 4 presents a rapid review of systematic reviews of randomized and non-randomized clinical trials and observational studies investigating associations between low- and no-calorie sweetener consumption and health outcomes and intermediate risk factors in adults and children. The search strategy returned 409 results, 25 of which met the eligibility criteria and underwent quality appraisal using the AMSTAR-2 assessment tool. Data from nine systematic reviews assessed as high- or moderate-quality were included in the narrative synthesis. Randomized controlled trials tended to report no association or beneficial impacts of consumption, whereas non-randomized trials and other observational studies observed no association or negative impacts on outcomes of interest, such as type 2 diabetes. There was limited evidence examining associations between consumption of sweeteners and diet quality. Chapters 5, 6, and 7 drew on 24-hour dietary recall data from the 2015 Canadian Community Health Survey—Nutrition Public Use Microdata File (2015 CCHS—Nutrition). In Chapter 5, a classification system was developed to categorize food codes used to code the 24-hour recalls as sources of sweeteners. First, food code descriptions were reviewed for confirmatory keywords, such as “low-calorie sweetener,” and possible source keywords, such as “diet.” Food codes with descriptions containing confirmatory keywords were categorized as sources, whereas those with descriptions containing possible source keywords progressed to step two. In step two, the descriptions for matching food codes in the U.S. Food and Nutrient Database for Dietary Studies were examined for confirmatory keywords. In step 3, the remaining possible sources were assessed using an online search of grocery store websites. A total of 76 food codes (1.5%) were classified as sources of low- and no-calorie sweeteners and 46 recipe codes used in the 2015 CCHS—Nutrition contained sources as ingredients. Steps 2 and 3 identified 41 food code sources not identified by Step 1 alone. In Chapter 6, the classification system was applied to recall data for individuals aged 1 year and above living in the Canadian provinces. The proportions reporting consumption of at least one source on a given day were estimated overall and by age, sex, household income, and self-reported diabetes status. Commonly reported sources were examined by age group, and the nutritional profiles of sources were examined relative to the 2019 Canada’s Food Guide. About one in 10 children aged 1-13 years (8.4%, 95% CI: 6.6, 10.2) and adolescents aged 14-18 years (10.7%, 95% CI: 7.6, 13.8) and one in five adults (19.8%, 95% CI: 16.2, 23.4) 19 years and above consumed sources of sweeteners on a given day. Among adults with diabetes, four in 10 (42.4%, 95% CI: 36.1, 48.7) consumed a source of low- and no-calorie sweeteners on a given day compared to approximately one in five (18.2%, 95% CI: 14.2, 22.0) who did not report having diabetes. Foods sweetened with low- and no-calorie sweeteners were more frequently consumed than beverages among children and adolescents (children: 5.5% (95% CI: 4.0, 7.0) vs. 3.1% (95% CI: 2.3, 3.9), respectively; adolescents: 6.2% (95% CI: 3.4, 9.1) vs. 4.1% (95% CI: 2.8, 5.4)), whereas adults consumed beverages more frequently than foods (10.9% (95% CI: 7.6, 14.2) vs. 7.7% (95% CI, 7.0, 8.4), respectively). On a given day, 4% of adults consumed tabletop sweeteners; estimates for children and adolescents were not reported due to small sample sizes. Diet sodas were the most frequently consumed beverage source across all three age groups. Yogurts were the most frequently consumed food source among children, whereas meal replacements, including protein powders, were the most frequently consumed food source among adolescents and adults. No food codes classified as sources of low- and no-calorie sweeteners were considered ‘foundational’ according to the 2019 Canada’s Food Guide Food Classification System. In Chapter 7, diet quality, measured using the 2019 Healthy Eating Food Index (HEFI-2019), was assessed in relation to the probability of consuming sources of low- and no-calorie sweeteners among respondents aged 2 years and older, overall and by sex and diabetes status. Higher HEFI-2019 scores, which represent closer alignment with the 2019 Canada’s Food Guide, were calculated based on simulated distributions of usual intakes estimated using the National Cancer Institute’s multivariate Markov chain Monte Carlo (MCMC) method. Variables (e.g. vegetables and fruit, free sugars) used to arrive at HEFI-2019 scores were modelled jointly with a variable indicating an individual’s probability to consume low- and no-calorie sweeteners on a recall day; probabilities of consumption were expressed as quintiles. There was weak evidence (P=0.08) of lower (-6.1 points, 95% CI: -13.1, 0.8) HEFI-2019 total scores among children aged 2 to 13 with the highest probability of consuming low- and no-calorie sweeteners (i.e. quintile 5) compared to children with the lowest probability. Among males 14 years of age and above, there was moderate evidence (P=0.04) of higher (4.6 points, 95% CI: 0.1, 9.1) HEFI-2019 total scores among those with the highest probability of consuming low- and no-calorie sweeteners compared to those with the lowest probability. There was no evidence of meaningful differences in HEFI-2019 total sores in relation to probability of consuming sources of low- and no-calorie sweeteners among females aged 14 years and above or among adults 19 years and above with and without diabetes. Conclusion: This dissertation makes several contributions to the evidence to inform policies related to low- and no-calorie sweeteners in Canada. First, the inconsistent associations between the use of sweeteners and health in the literature contribute to differing dietary guidance across health authorities. This lack of clarity on how and by whom low- and no-calorie sweeteners should be consumed emphasizes the importance of ongoing monitoring of population-level consumption patterns. Second, this dissertation presents a standardized approach to identifying sweetener sources in Canada’s national food composition database, enabling consistent classification across studies. Third, for the first time, evidence on population-level exposure to low- and no-calorie sweeteners from foods, beverages, and tabletop sweeteners in Canada and associations between diet quality and the probability of consuming low- and no-calorie sweeteners can inform healthy eating policies, such as Canada’s Healthy Eating Strategy.

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