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

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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.

Tobacco industry targeting of youth in Nigeria since the 1990s: An analysis of tobacco industry documents

Author: 
Date created: 
2017-10-19
Abstract: 

This study analyses the tactics and strategies used by transnational tobacco companies (TTCs) to target youth in Nigeria since the 1990s. Nigeria is considered by the tobacco industry to be a major emerging market given its population, demographic profile, and growing wealth. The study systematically searched the Truth Tobacco Industry Documents Library, available primary and secondary sources on industry activities in Nigeria, and conducted key informant interviews. It applied the theory of triadic influence as a heuristic framework to analyse the collected data. The findings suggest that TTCs have actively targeted youth in Nigeria, seeking to change behaviour through the biological/personality, and environmental/cultural and social streams. This has taken place against a backdrop of weak tobacco control policy despite Nigeria’s adoption of the Framework Convention on Tobacco Control. The study makes recommendations to strengthening youth protections under the National Tobacco Control Bill adopted into law in 2015.

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

Cancer risk among women living with HIV: Implications for care in the modern cART era

Author: 
Date created: 
2017-06-28
Abstract: 

Following the advent of modern combination antiretroviral therapy (cART) in 1996, a temporal decline was widely observed in AIDS-related morbidity and mortality. In the province of British Columbia (BC), universal provision of cART free-of-charge for people living with HIV (PLHW) has contributed in part to a significant demographic shift, with individuals over 50 years of age comprising over half of all PLHW. In this context there is a need to understand how comorbidities, such as cancer, impact this aging cohort. Within this line of inquiry, it is imperative to look at cancer risk specifically amongst women living with HIV (WLWH). The majority of studies looking at cancer as a co-morbid condition among PLWH fail to conduct sex-stratified analyses, which may obscure the burden of cancer risk specific to WLWH. Using a Life Course Epidemiology framework, the objectives of this PhD dissertation were to: 1) measure cancer incidence among WLWH in BC compared to a general population sample of women; 2) identify the role of early cART initiation in mitigating excess risk of cancer observed among WLWH; and 3) estimate the burden of cancer-related mortality among PLWH. This research utilized administrative health data from Population Data BC (which included data from the BC Cancer Agency and Vital Statistics) and clinical HIV data from the BC Centre for Excellence in HIV/AIDS. Findings suggest WLWH experience an increased risk of certain cancers, notably for certain viral-related malignancies, in comparison to HIV-negative women in the modern cART era. A protective effect of early initiation of cART therapy was found for some types of cancer, suggesting oncological health benefits might be associated with timely initiation of cART after HIV diagnosis for WLWH. Finally, sex stratified age-adjusted cancer-related mortality rates promisingly suggest there may not be significantly different cancer-related mortality outcomes between PLWH and the general population. This dissertation demonstrates that cancer-related morbidity is a healthcare priority for the growing aging demographic of WLWH and subsequently highlights the importance of appropriate and effective routine cancer screening measures as well as comprehensive HIV care inclusive of timely diagnosis and cART initiation.

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

Going beyond health-related quality of life for outcome measurement in economic evaluation

Author: 
Date created: 
2017-07-04
Abstract: 

Background: The quality-adjusted life year (QALY) framework has been challenged for use in economic evaluation because of its narrow focus on health-related aspects of quality of life, thus ignoring potential ‘non-health’ benefits associated with treatments and interventions. With the development of new preference-based measures, such as the ICEpop CAPability (ICECAP) instruments that adopt a broader evaluative space, the aim of this thesis was to examine methodological considerations and applied implications for outcome measurement in health economics when applying measures that extend beyond health. Methods: A narrative review provides an overview of challenges involved for broadening the evaluative space of the QALY and the progress that has been made in this area. A critical interpretive synthesis (CIS) is then presented that conceptualized benefits beyond the health-related QALY, followed by three empirical analyses, each using a different dataset: (i) regression analyses testing the complementarity of a preference-based health-related quality of life (HRQoL) measure, the EQ-5D-5L, and a measure of capability wellbeing for older adults, the ICECAP-O, within the context of public health; (ii) exploratory factor analyses investigating the overlap between the ICECAP-A and five preference-based HRQoL measures; and (iii) path analyses to further explore the relationship between two HRQoL measures (EQ-5D-5L and AQoL-8D) and two wellbeing measures (ICECAP-A and subjective wellbeing). Results: The CIS conceptualized non-health benefits into four themes: (i) benefits affecting a person’s wellbeing (psychological wellbeing, subjective wellbeing, empowerment, and capability wellbeing); (ii) benefits derived from the process of health care delivery; (iii) benefits beyond the affected individual; and (iv) benefits beyond the health care sector. Three key findings were made from the empirical analyses that further explored wellbeing measures. Firstly, the ICECAP-O is more sensitive to environmental features (i.e., social cohesion and street connectivity) when compared with the EQ-5D-5L; secondly, the ICECAP-A contains domains in its descriptive system that are not measured by most HRQoL measures, except for the AQoL-8D; and thirdly, HRQoL and wellbeing measures are affected in a different way by different secondary health conditions but a similar relationship was found between the ICECAP-A and AQoL-8D. Conclusion: The thesis concludes that the application of wellbeing measures in economic evaluations requires careful consideration due to the risk of double counting. The capability approach has the potential to extend the QALY but the operationalization of this approach – and other non-health benefits within or outside the QALY framework – requires further research.

Document type: 
Thesis
File(s): 
Senior supervisor: 
David Whitehurst
Scott Lear
Department: 
Health Sciences: Faculty of Health Sciences
Thesis type: 
(Thesis) Ph.D.