Health Sciences - Theses, Dissertations, and other Required Graduate Degree Essays

Introduction: In 2012, the Supreme Court of Canada (SCC) expanded the reach of criminal liability for HIV non-disclosure in Canada when it ruled that people living with HIV (PLWH) who do not disclose their HIV status before sex that has a “realistic possibility” of HIV transmission could face criminal charges, suggesting that condom-protected vaginal sex with a low HIV viral load would incur no legal obligation to disclose. This thesis sought to identify the prevalence and correlates of facing a legal obligation to disclose, and to investigate awareness, understanding and perceived healthcare impacts of the 2012 SCC ruling among the diversity of women living with HIV (WLWH) in Canada, involving WLWH as key research partners.Methods: Quantitative data from men and women enrolled in a cohort of PLWH who use illicit drugs in Vancouver (ACCESS), and women enrolled in a community-collaborative cohort of WLWH in British Columbia, Ontario, and Quebec (CHIWOS), were used to meet the objectives of this thesis. Novel community-driven questions assessing awareness, understanding and perceived impacts of HIV non-disclosure case law were incorporated into data collection instruments of both cohorts. Results: Among ACCESS participants who use injection drugs (n=176), WLWH were more likely to face a legal obligation to disclose compared to men in the wake of the 2012 SCC ruling. Among female ACCESS (n=98) and CHIWOS (n=584) participants, awareness of the 2012 SCC ruling (44% and 74%, respectively) and understanding of the conditions under which PLWH may face a legal obligation to disclose (17% and 35%, respectively) were suboptimal. Although most participants were engaged in HIV treatment and care, discussions about HIV disclosure and the law were lacking in healthcare settings, despite participants expressing a willingness and desire to engage in discussions of this nature with providers. Most participants believed that HIV non-disclosure case law might limit the type of information WLWH would share with providers.Discussion: This thesis identified an urgent need to disseminate information about HIV non-disclosure and the law in community and healthcare settings, to ensure WLWH have fundamental information to avoid prosecution and to optimise their health and rights in the current legal climate.

Background: Antiretroviral therapy (ART) and ambitious treatment strategies such as Treatment as Prevention (TASP) and 90-90-90 have reduced HIV-related morbidity and mortality among people living with HIV (PLWH), and substantially decreased the likelihood of transmission of the virus to others. The benefits of ART are not felt equally among all PLWH, as PLWH may not be able to maintain ART adherence. This study examines gender differences in ART adherence and the sociostructural and psychosocial factors associated with such differences in British Columbia, Canada. Methods: Quantitative analyses assessed optimal ART adherence by gender, longitudinally and cross-sectionally, using bivariate, multivariate analyses, as well as structural equation modelling. All analyses used data collected from 2000 onward by the BC Centre for Excellence in HIV/AIDS from BC, Canada, with adherence measured using pharmacy refill compliance data. Findings: Gender-based disparities were evident in ART adherence in BC, with a significantly lower proportion of women attaining optimal (≥95%) adherence relative to men (57.0% versus 77.1; p<0.001) regardless of subgroup. Women also experienced far greater sociostructural and psychosocial disparity than men, however food insecurity was the only variable examined that was independently associated with suboptimal adherence among women (adjusted odds ratio [AOR]: 0.364; 95% confidence interval [CI]: 0.181 to 0.734). Psychosocial variables exhibited different effects and interactions for men and women, however, they explained only a low proportion of the variability observed in ART adherence (1.6% and 3.7%, respectively). Disclosure worries was the only psychosocial variable to affect women’s adherence (standardized regression weight [r]: -0.192; p=0.015). Personalized stigma (r: 0.299; p<0.001) and internalized stigma (r: 0.321; p<0.001), however, did have a significant explanatory affect on depression experienced by women. Discussion: Gender-based disparities must be addressed if women living with HIV are to attain optimal health and if we are to achieve the goals of 90-90-90. Addressing aspects of poverty and the greater adversity that women face in this regard would result in a more salient improvement to ART adherence than interventions addressing stigma.

Homeless mothers represent an extremely vulnerable population. Research consistently revealed that they experience poor quality of life (QoL) and increased depression. Evidence also indicated that increased QoL is associated with improvements in depression. Whether the effect of parenting status on depression is mediated by QoL is unclear. This study, therefore, examined how parenting status affects depression among homeless women, through subjective quality of life (SQoL). This secondary analysis drew from the 325 chronically homeless women who completed the At Home/Chez Soi Study baseline questionnaire. Associations were examined using bivariate analyses and mediation analyses were performed using bootstrapped regression models. SQoL explained the association between parenting and depression; leisure accounted for the largest proportion (27%) of the variance on depression. The findings highlighted the importance of providing supports to homeless mothers, so as to improve their SQoL and depression. Specifically, findings suggested that leisure could partially improve depression among homeless mothers.

Although evidence suggests that depression is one of the leading causes of morbidity and disability in the world, treatment for depression is often unavailable, especially in low and middle-income countries. This gap in treatment has led to momentum to improve and scale-up services through approaches such as task-shifting. These steps, however, must be carefully considered to ensure that such efforts are appropriate, effective and acceptable for populations being served. This dissertation assesses barriers and facilitators to the integration of services for depression in primary care in Vietnam from the perspective of primary care providers (PHPs) by examining sociocultural considerations and individual, organizational and structural factors that might influence the process of service integration. The study has three components. The first, a narrative review, explores considerations for studying depression cross-culturally and the implications for global depression research. The results suggest that although depression is universally experienced, it varies by cultural context, and improved epidemiological methods that account for these cross-cultural variations are needed. The relationship of social determinants of health to depression must also be further explored. The second component, a qualitative study, examined how depression is conceptualized in Vietnam from the perspective of PHPs. Findings indicate that although depression is not widely recognized or seen in primary care, depression in Vietnam is largely understood in psychosocial terms. Along with efforts to improve screening and help-seeking, the introduction of psychosocial depression interventions in primary care is both appropriate and important. The third component used mixed methods to assess barriers and facilitators to the integration of services for depression in primary care. The findings suggest that although PHPs are motivated to build capacity and deliver services for depression for their patients, systemic factors must be addressed to ensure that PHPs are adequately trained and supported to deliver psychosocial interventions. By integrating an approach that examines sociocultural considerations of depression with individual, organizational and structural factors influencing service integration, this study suggests that a balance is both necessary and possible between approaches prioritizing efficient treatment delivery and those emphasizing the need for contextualization and careful sociocultural consideration. A balance of these approaches should be applied when introducing enhanced depression services cross-culturally.

Reproductive behaviors are shaped by a plethora of selective pressures, past and present. On an ecological time scale, reproductive “decisions” are made by balancing life-history trade-offs that are dependent on intrinsic and extrinsic factors, such as resource availability and age. Mathematical models are powerful tools that allow for the systematic investigation of such factors, and to test whether selective forces thought to be responsible for particular traits had been correctly identified. In this thesis, I present a dynamic state variable model for the optimization of reproductive scheduling under a range of family and environmental contexts. Next, I test one of the model’s simplifying assumptions, that sons and daughters cost the same to produce and to raise, via secondary data analysis of two existing data sets. These results are discussed in parallel to the benefits of applying principles of evolutionary ecology to public health problems.

Background: Reducing malaria mortality is a global priority. Uganda has focused its national strategic plan to have by 2010: 85% of children under five receive first-line antimalarials within 24 hours of fever onset and following diagnostic confirmation. In 2004, artemisinin-combination therapies (ACTs) were adopted as first-line treatment for uncomplicated malaria in children older than 4-months. Method: A three-study series investigated caregivers’ malaria related treatment-seeking behaviors for young children to inform future public health initiatives in Uganda’s Butaleja District: a literature review, a household survey, and a multiple case study. In this document, these appear as three manuscripts in Chapters 2-4. Results: While drug delivery improvements have increased ACT usage, these studies concur that initiatives still failed to meet the 2010 national target. Only 21% of children received blood tests, 31.6% received no antimalarials, 31.6% received “appropriate” (only first-line) antimalarials, and 36.8% received subordinate antimalarials. Among subordinates, 5.8% of children were mis-prescribed ACTs and 22.4% received ACTs and subordinate antimalarials. Home management was an important initial treatment source since visits to public facilities were commonly associated with hardships. Caregivers’ knowledge and preference about antimalarials varied with prior experiences and beliefs. The survey evaluated 160 behavioral questions in determining four independent predictors of likelihood that a child would receive an “appropriate” antimalarial: obtaining antimalarials from regulated outlets (OR=14.99); keeping ACT in the home for future use (OR=6.36); reporting they would select ACT given the choice (OR=2.31); and child’s age older than 4 months (OR=5.67). The study further employed the Health Belief Model to identify 10 scales of “Assets” and “Challenges” to guide more precise insights into caregivers’ behaviors. Four “Asset” scales predicted significantly whether a child received an “appropriate” antimalarial: Precursors to Receiving an Appropriate Antimalarial (R2=21%); Episode Management (R2=39%); Caregiver Knowledge (R2=6%); and Professional Assistance with Critical Decision (R2=9%). Similarly, two “Challenge” scales were significant predictors: Lack of Assistance with Critical Decision (R2=9%), and Problems Obtaining a Best Antimalarial (R2=4%).Conclusions: To conform practice to policy, this research sequence highlighted the importance of engaging the full spectrum of stakeholders in public health initiatives to manage malaria, including licensed and unlicensed providers, caregivers and family members.

Introduction: Childhood injuries represent a significant public health problem, with young children being injured in often predictable ways. Injury surveillance – not currently done in Canada – could track the population burden and help identify factors amenable to prevention. Methods: A systematic review of the childhood injury incidence literature was conducted using methods adapted from the Cochrane Collaboration. Particular attention was paid to identifying injuries according to developmentally sensitive age groupings to avoid masking the incidence of specific injury types in younger children. Results: Eight incidence studies met appraisal criteria. The highest injury rate was 375 per 1,000 one-year-old boys in Alberta. Despite variability in data sources and reporting methods, it was possible to use these findings to suggest new approaches to child injury surveillance that are developmentally sensitive and grounded in ecological approaches to understanding injury etiology. Discussion: The implications for child injury research, prevention, and surveillance in Canada are reviewed.

While the rights of gay men have improved significantly over the past 40 years, the health inequities of this diverse population remain considerable and efforts to reverse the trend have yielded few results. This suggests that a radical shift is warranted into how we theorize, investigate and intervene in this area. Public health researchers have primarily focused on gay men’s behaviours to explain negative health outcomes while social factors have been largely neglected. To change this trend, intersectionality has been proposed as a framework to study gay men’s health inequities. Intersectionality promotes an understanding of humans as being shaped by the interaction of different social locations and structures of power. It is now recognized as an important framework to study health inequities. However, marginalized and multiply oppressed women are still the primary focus of much intersectional scholarship and the literature exploring the relationship between intersectionality and gay men’s health is still underdeveloped. Therefore, more work is needed theoretically, methodologically and empirically to grasp the potential contributions of intersectionality to the understanding of how health inequities of gay men are produced and sustained. In this dissertation I explore how intersectionality can help transform the field of gay men’s health research, and help attend to issues of gay men’s health inequities more effectively. This was accomplished by uniting in one collection three case studies, each looking at how intersectionality can transform a different aspect of research: theorizing, methodology, and data analysis. Together, the three case studies demonstrate that intersectionality can 1) disrupt essentialist assumptions and the false homogenization of gay men in public health research and therefore bring forward issues of diversity more effectively; 2) illuminate interactive power dynamics affecting gay men’s health such as systemic heterosexism, sexism, and racism as well as power differences operating within gay communities such as racism, classism and misogyny; 3) produce new and more accurate knowledge about health inequities due to its attention to multiple and intersecting factors. In light of these results, I conclude that intersectionality is more than a useful framework for gay men’s health research; it is critical to reversing gay men’s health inequities.

This study sought to better understand mentoring in the training of the public health workforce, and to identify key issues in the conceptualization and application of mentoring and its potential relevance to public health. Methods entailed a scoping review of literature in Medline, CINAHL, and Web of Science databases following guidelines in the PRISMA standards. A total of 1809 references between 2000 and June 2014 were identified, of which 27 met inclusion criteria. Very little research on the topic has been published. The main thematic areas were the models used in mentoring, the value of mentoring, mentors' and mentees' perceptions and needs, attributes of successful mentoring relationships, elements for the design and evaluation of mentoring programs, and authors’ recommendations. The main conclusion is that mentoring is a growing interest in relation to developing the public health workforce. To improve mentoring models and practices, further research should be conducted.

Background: More than thirty years after the beginning of the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic, HIV continues to be a problem among adolescents and young adults (AYA).. The benefits of combination antiretroviral therapy (cART), including lower morbidity and improved survival, are realized through timely uptake of treatment, virological suppression, and retention in care; however, compared with their adult counterparts, AYA living with HIV tend to have poorer treatment and clinical outcomes. In the current context of UNAIDS’ ambitious 90-90-90 campaign, there is a push to expand cART to all those in need in order to reduce morbidity/mortality and to curb transmission of HIV. We will not achieve the 90-90-90 goals without addressing HIV treatment and outcomes among AYA; however this population remains under-researched; to date there is very little research describing AYA living with HIV in Canada. The overall aim of this dissertation is to examine key cART treatment outcomes among Canadian AYA (ages 18-29 years) living with HIV and compare outcomes with those of older adults (30 years and older). Methods: The quantitative studies in this dissertation utilize clinical and laboratory data from the Canadian Observational Cohort Collaboration (CANOC), Canada’s largest HIV cohort study, which includes data from the year 2000 onward on a total of 10,044 people living in three of Canada’s largest provinces—British Columbia, Ontario, and Quebec. All participants in CANOC are HIV-positive and were cART-naive prior to initiating antiretroviral treatment on or after January 1, 2000. Findings: There are 1168 (13.7%) AYA (ages 18-29 years) in CANOC. Significant differences in treatment outcomes were found between AYA and older adults. AYA were more likely than older adults to initiate cART before their CD4 counts were <200 cells/mm3 and/or they had an AIDS-defining illness (ADI) (51.7% vs 40.2% p<0.001). When looking at virological suppression, fewer AYA experienced virological suppression than older adults (86% vs. 91%, p<0.001) and of these, only 73% (compared with 80% of older adults) suppressed within the first year of cART inititation (p<0.001). Additionally, a greater proportion of AYA who achieved virological suppression experienced viral rebound than older adults (26% vs. 22%, p=0.009). Discussion: When comparing AYA with older adults, AYA are more likely to initiate treatment when recommended but once on treatment, they are less likely to virologically suppress and remain suppressed. The importance of supporting AYA to achieve optimal health is a long-term investment with benefits over the life course. In order to meet ambitious public health goals such as those that the UNIADS 90-90-90 campaign has set, AYA will require tailored health care services and programming to assist them to access and remain in care.