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

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Examining the social, sexual, and technological behaviour of gay, bisexual, and other men who have sex with men

Date created: 
2018-04-04
Abstract: 

Online sex seeking (OSS) has previously been associated with condomless anal sex (CAS) among gay, bisexual, and other men who have sex with men (GBM). Previous studies suggest that this association may be due in part to the uptake of OSS among GBM who are more likely to engage in CAS. This thesis examines the interpersonal factors that might underlie this association. Data for this thesis was collected through the Momentum Health Study, a longitudinal cohort of GBM living in Metro Vancouver and recruited using Respondent-Driven Sampling. Latent class analysis, hierarchical regression, and structural equation models examined (i) patterns of online and offline community connectedness, (ii) covariates of event-level CAS within the context of online-initiated partnerships, and (iii) confounding effects of collectivism on the OSS-CAS relationship. Latent modeling of patterns of community connectedness identified three classes: Class 1, “Socialites,” (38.8%) were highly connected both online and offline. Class 2, “Traditionalists,” (25.7%) were moderately connected with little app/website-use. Class 3, “Techies,” (35.4%) had high online connectedness and relatively low in-person connectedness. In multivariable modelling, Socialites had higher collectivism than Traditionalists, who had higher collectivism than Techies. Patterns of community connectedness were also related to HIV-testing, perceptions of HIV stigma, serodisclosure, and condom use. Supporting these findings, hierarchical event-level logistic regression showed that collectivism, altruism, and social embeddedness were protective factors against CAS – particularly for HIV-negative men. Structural equation modelling revealed that collectivism, altruism, and sensation seeking accounted for approximately 40% of the association between OSS and CAS. In conclusion, these analyses suggest that collectivism, and related sociocultural constructs, promotes greater adherence to established HIV-prevention practices (such as condom use) while individualism may be more amenable to novel risk-reduction strategies which may or may not include condoms. While further research is needed to understand the plasticity of these interpersonal factors, these results suggest that programs facilitating collectivism might have the potential to establish broad sexual health norms. Furthermore, sex-positive risk reduction is likely an important component of HIV prevention for GBM who are less attuned to traditional social influences – many of whom predominantly use the Internet to connect with other GBM.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Robert S. Hogg
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) Ph.D.

The Case of "Molar City", Mexico: An Ethical Examination of Medical Tourism Industry Practices

Author: 
Date created: 
2017-12-06
Abstract: 

“Molar city” or Los Algodones, Mexico is characteristic of other medical border towns whose proximity to the Mexico-United States border enables American and Canadian patients to access desired health care. Patients can take advantage of economic asymmetries on either side of the border to purchase desired health care in an easily accessible location. Los Algodones is an exceptional industry site in northern Mexico, however, due to its focus on the provision of dental care and claims by local residents that it has the highest concentration of dentists per capita in the world. In this dissertation, I use a case study of Los Algodones’ dental tourism industry to provide an examination of ethical concerns for medical tourism industry practices. Drawing on findings from qualitative research exploring the perspectives and experiences of diverse industry stakeholders, this study contributes insight into ethical examinations for medical tourism informed by structural exploitation and structural injustice frameworks. By employing these ethical frameworks to examine one particular industry site, this research outlines how structural factors such as competition in the global industry and economic asymmetries between the global north and global south inform unfair localized industry practices. I highlight in this dissertation how industry practices are taken up by various industry stakeholders to maintain the flow of dental tourists to Los Algodones; however, efforts to promote and protect the success of the industry according to the interests of elite industry stakeholders inform practices characterized by the irresponsible use of health resources and degrading interactions. Overall, this research suggests that medical tourism industry development raises health equity concerns for the industry if exploitative practices in different industry sites produce poor labour conditions and access to care barriers for marginalized populations. Further research is needed to explore the utility of these ethical frameworks when examining other industry sites and possible policy implications for mitigating exploitative practices within different contexts of industry development.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Jeremy Snyder
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) Ph.D.

The distribution and determinants of hospital readmission among people living with HIV/AIDS in British Columbia, Canada

Author: 
Date created: 
2018-01-11
Abstract: 

Unplanned hospital readmissions are costly and common among people living with HIV/AIDS (PLWHA). However, factors associated with readmission remain poorly understood. The purpose of this study was to examine the distribution and risk factors of 30-day readmission among the population of PLWHA in British Columbia, Canada. A retrospective cohort study using linked administrative data was executed with multivariable logistic regression models to identify risk factors of readmission. Approximately 14 percent of all hospitalizations resulted in 30-day re-hospitalization, 5.5% higher than the readmission rate for the general population in Canada. Four enabling factors (longer length of stay in the index hospital admission, admission via emergency departments, leaving against medical advice, transferring between hospitals); one need factor (latest CD4 count prior to admission) and one predisposing factor (diagnostic category) were associated with an elevated odds of readmission. Policymakers should develop strategies focusing on modifiable risk factors to decrease hospital readmission among PLWHA.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Bohdan Nosyk
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) M.Sc.

Epidemiological and experimental evidence to improve antipsychotic medication adherence among patients with schizophrenia who are homeless and involved with the criminal justice system

Date created: 
2017-02-08
Abstract: 

Background: Schizophrenia consistently ranks among the leading causes of disability worldwide, and is significantly overrepresented in socially disadvantaged populations. Despite demonstrated efficacy of antipsychotic medication in research studies, poor adherence limits its effectiveness in real-world practice. Remarkably, antipsychotic adherence has never been examined in homeless or justice-involved patient cohorts under naturalistic conditions, and current treatment guidelines provide little information on practices to improve outcomes in these important subgroups. The three original research studies that comprise this thesis address this substantial omission in existing literature. Methods: The studies include population-level analysis, retrospective cohort design and a randomized controlled trial. Offenders diagnosed with schizophrenia, prescribed antipsychotic medication and convicted under British Columbia jurisdiction were the basis for longitudinal epidemiological analysis. A homeless cohort of Vancouver patients with severe mental illness enabled retrospective analysis of antipsychotic use, and examination of changes in adherence following randomization to different supported-housing treatment conditions. All three analyses drew on a centralized administrative repository of comprehensive prescription details. Adherence was operationalized using the medication possession ratio (MPR). Results: Over an average follow-up of 10 years, findings from the offender sample (n=11,462) revealed a mean MPR of 0.41. Results further demonstrated that patients who met guideline-level adherence (MPR≥0.80) were significantly less likely to be convicted of both violent and non-violent offences. 15-year retrospective analyses of homeless patients also showed an average MPR of 0.41. Higher antipsychotic adherence was significantly associated with duration of homelessness, prescription of long-acting injectable medication and primary care engagement. Randomization to market housing with assertive community treatment resulted in near guideline-level adherence (0.78), while assignment to congregate supported-housing and treatment as usual led to relatively low levels of adherence (0.55 and 0.61, respectively). Conclusion: Results demonstrate that homeless and/or justice-involved patients with schizophrenia have very low levels of adherence to prescribed antipsychotic medication. Findings were corroborated using two separate samples, in the context of universal health care, where prescribed medication is provided at no cost to patients of limited means. Action is needed to implement measures including those detailed in this research that have demonstrated promise to improve adherence among highly vulnerable patient groups.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Julian Somers
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) Ph.D.

Guides and Guilds in the Labyrinth: Perspectives of Labour Advocates on BC's Work Disability System

Author: 
Date created: 
2017-11-20
Abstract: 

This thesis surveys the work of BC’s unions in representing members with disability and return to work concerns, document union perspectives on these issues and identify the key policy priorities they believe should be the focus of future disability research in the province. The Centre for Research on Disability Workplace Policy (CRWDP) is a partner and supporter of this research. The key questions asked by this study are: “From the perspective of people who work in organized labour to represent workers with disabilities... (1) what are the experiences of people who work in organized labour to represent workers with disabilities?” ...what is the state of BC’s work disability system?” (2) what are the gaps or failings of BC’s work disability system?” and (3) what are the priorities for change within BC’s work disability system?” The purpose of answering these questions is to better understand and, hopefully, improve the experiences of people with work-related disabilities. Improved coordination of the work disability system and a better understanding of what gaps exist may help accomplish this. Furthermore, opportunities to better coordinate the efforts of the labour community may arise out of gaining an understanding of what labour disability advocates in organized workplaces do across the province. Finally, this study informs decisions around needed changes in the system.

Document type: 
Thesis
File(s): 
Senior supervisor: 
John Calvert
Maya Gislason, Marina Morrow, & Tim Takaro
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) M.P.H.

Recent Cancer Screening Among Women: A Critical Evaluation of Why Canadians aren’t Getting Regular Clinical Breast Exams and Pap Tests

Author: 
Peer reviewed: 
No, item is not peer reviewed.
Date created: 
2009-08
Abstract: 

Preventive cancer screening is effective for early detection of many cancers, however many Canadians fail to participate in screening programs. This paper critically evaluates the results of an analysis of Canadian Community Health Survey data relating to women‟s cancer screening behaviours. The most commonly reported reasons by Canadian women for not being screened by clinical breast exams (CBE) and Pap tests are discussed in relation to their ability to provide insight into why women do not participate in cancer screening. Limitations of current data on cancer screening behaviours are discussed along with recommendations for their improvement.

 

Document type: 
Thesis
File(s): 
Senior supervisor: 
Kate Bassil
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) M.Sc.

Structural maintenance of Chromosome Hinge Domain Containing 1 (SMCHD1) regulates gene expression

Author: 
Date created: 
2017-11-17
Abstract: 

Eukaryotic cells evolved by packaging genomic DNA into chromatin where DNA is wrapped around histones. This significantly reduces random transcriptional events by providing a barrier for gene expression. In addition, chemical modifications of histones and cytosine residues on DNA greatly impact regulation of gene expression. Structural maintenance of chromosome hinge domain containing 1 (SMCHD1) is a chromatin modifier. SMCHD1 was originally recognized as essential for X chromosome inactivation and survival in female mice where it plays a critical role in methylation of a subset of CpG islands. Structural studies suggest that SMCHD1 interaction with HP1 binding protein, HBiX1, mediates heterochromatin formation over the X chromosome by linking two chromatin domains enriched for repressive histone marks. In addition, loss of SMCHD1 is lethal in male mice in a mixed background, implying that SMCHD1 regulates genes on non-sex chromosomes. Thus, we identified a need to investigate the role of SMCHD1 in regulating expression of autosomal genes. In addition, I sought to determine SMCHD1 genome occupancy when global DNA methylation was greatly reduced and identify candidate binding partners. I used shRNA technology to knockdown SMCHD1 expression and identified genes that were up and down regulated in human embryonic kidney (HEK293) cells. A number of these genes are expressed in either a stochastic or parent-of-origin monoallelic fashion. Using chromatin immunoprecipitation-sequencing (ChIP), I identified genome-wide occupancy of SMCHD1 and showed that its genomic binding was sensitive to the DNA demethylating reagent, 5-azacytidine. SMCHD1 occupancy correlates with a number of genes belonging to the G protein-coupled receptor superfamily and loss of SMCHD1 in human neuroblastoma SH-SY5Y cells leads to increased levels of cellular cAMP. In addition, loss of SMCHD1 increases KCNQ1 expression, a subunit of the potassium voltage gated channel that plays a critical role in repolarization of the cardiac action potential. Moreover, using tandem tagged affinity purification, I investigated binding partners that potentially interact with SMCHD1 to regulate gene expression. Taken together, SMCHD1 might be involved in variety of diseases including Facioscapulohumeral Muscular Dystrophy (FSHD) and Bosma Arhinia Microphthalmia Syndrome (BAMS).

Document type: 
Thesis
Senior supervisor: 
Gratien Prefontaine
Timothy Beischlag
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) Ph.D.

Understanding our past, reclaiming our culture: Conceptualizing Métis culture and mental health in British Columbia

Date created: 
2017-08-03
Abstract: 

Despite reported disparities in mental health for the Métis population, as well as the historic and contemporary challenges that many Métis people face in maintaining cultural connectedness, cultural continuity research with Métis communities remains largely ignored. To address this gap, this research sought to explore the meaning of cultural continuity and mental health for Métis people in British Columbia (BC). This thesis includes a meta-synthesis of relevant, original research with Indigenous Peoples in Canada and the United States, and a grounded theory study that explores Métis participants’ experiences and conceptualizations of mental health and cultural continuity. Through the development of a Métis cultural continuity framework and evidence that associates cultural continuity as a Métis determinant of health, the findings point to the need for conducting community-driven quantitative research, in addition to supporting cultural practices, language revitalization, and Elder-youth engagement opportunities for increased cultural continuity for Métis people in BC.

Document type: 
Thesis
File(s): 
Senior supervisor: 
John O'Neil
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) M.Sc.

Kidney Transplant Outcomes for Prolonged Cold Ischemic Times in the Context of Kidney Paired Donation

Date created: 
2017-07-21
Abstract: 

The need for kidneys outweighs the current organ supply. This study examines the impact of longer cold ischemic time (CIT) on graft outcomes to help expand living donor transplantation in kidney paired donation (KPD). In a retrospective cohort study of 48,498 living donor (LD) recipients in the United States between 2005-15, multivariate survival analyses reveal no association between CIT <16 hours for all-cause graft loss, or death-censored graft loss (hazard ratios for CIT 8.0-16.0 hours (0.97; 95% CI 0.74-1.26) and (1.09; 95% CI 0.81-1.48) respectively, compared to CIT 0.1-2.0 hours). These results were robust in LD >50 years and in KPD and non-KPD transplants. While there was a higher incidence of delayed graft function (DGF) in groups with longer CIT, the overall incidence of DGF was low. Multivariate regression analyses show increased odds of DGF only in CIT 8.1-16 hours compared to 0.1-2.0 hours (odds ratio: 1.47; 95% CI 1.05-2.05).

Document type: 
Thesis
File(s): 
Senior supervisor: 
Malcolm Steinberg
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) M.P.H.

Modelling Fine Particulate Matter Concentrations inside the Homes of Pregnant Women in Ulaanbaatar, Mongolia

Author: 
Date created: 
2017-06-30
Abstract: 

Fine particulate matter (PM2.5) is a leading public health risk factor globally. Indoor concentrations are an important determinant of exposure because people spend the majority of time indoors. I developed models for predicting PM2.5 concentrations inside the homes of pregnant women in Ulaanbaatar, Mongolia. The work was part of a randomized controlled trial of portable air cleaner use during pregnancy, fetal growth, and early childhood development. Multiple linear regression (MLR) and random forest regression (RFR) were used to model indoor PM2.5 concentrations using 7-day indoor PM2.5 measurements and potential predictors obtained from outdoor monitoring data, questionnaires, home assessments, and geographic data sets. The MLR (R2 = 50.5%) and RFR (R2 = 47.8%) models explained a moderate amount of variation in log-transformed indoor PM2.5. Model predictions can be used to evaluate associations between indoor PM2.5 concentrations during pregnancy and development in early life.

Document type: 
Thesis
File(s): 
Senior supervisor: 
Ryan Allen
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) M.Sc.