4. Electronic Theses and Dissertations (ETDs) - Faculties submissions
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Item Predicting in-hospital mortality in heart failure patients using machine learning(University of the Witwatersrand, Johannesburg, 2023-05) Mpanya, Dineo; Ntsinjana, HopewellThe age of onset and causes of heart failure differ between high-income and low-and-middle-income countries (LMIC). Heart failure patients in LMIC also experience a higher mortality rate. Innovative ways that can risk stratify heart failure patients in this region are needed. The aim of this study was to demonstrate the utility of machine learning in predicting all-cause mortality in heart failure patients hospitalised in a tertiary academic centre. Six supervised machine learning algorithms were trained to predict in-hospital all-cause mortality using data from 500 consecutive heart failure patients with a left ventricular ejection fraction (LVEF) less than 50%. The mean age was 55.2 ± 16.8 years. There were 271 (54.2%) males, and the mean LVEF was 29 ± 9.2%. The median duration of hospitalisation was 7 days (interquartile range: 4–11), and it did not differ between patients discharged alive and those who died. After a prediction window of 4 years (interquartile range: 2–6), 84 (16.8%) patients died before discharge from the hospital. The area under the receiver operating characteristic curve was 0.82, 0.78, 0.77, 0.76, 0.75, and 0.62 for random forest, logistic regression, support vector machines (SVM), extreme gradient boosting, multilayer perceptron (MLP), and decision trees, and the accuracy during the test phase was 88, 87, 86, 82, 78, and 76% for random forest, MLP, SVM, extreme gradient boosting, decision trees, and logistic regression. The support vector machines were the best performing algorithm, and furosemide, beta-blockers, spironolactone, early diastolic murmur, and a parasternal heave had a positive coefficient with the target feature, whereas coronary artery disease, potassium, oedema grade, ischaemic cardiomyopathy, and right bundle branch block on electrocardiogram had negative coefficients. Despite a small sample size, supervised machine learning algorithms successfully predicted all-cause mortality with modest accuracy. The SVM model will be externally validated using data from multiple cardiology centres in South Africa before developing a uniquely African risk prediction tool that can potentially transform heart failure management through precision medicine.Item The potential of zingerone to protect against alcohol-induced liver disease(University of the Witwatersrand, Johannesburg, 2023-05) Asiedu, Bernice; Chivandi, Eliton; Nyakudya, Trevor; Lembede, BusisaniAlcohol can cross the placental blood-barrier and can also be secreted into breast milk. This can affect developing foetuses and/or nursing neonates negatively, thus impacting on metabolic health in early or later life. Zingerone (ZO) has anti-oxidant, anti-diabetic, anti-inflammatory, hypolipidaemic and hepato-protective properties. I hypothesised that neonatal oral administration of ZO could programme for protection against alcohol-induced metabolic derangements in suckling Sprague-Dawley (SD) rat pups mimicking human neonates that indirectly consume alcohol through their mother’s breast milk. The first experiment evaluated ZO’s potential to protect suckling rat pups against alcohol-induced metabolic derangements. Seventy 10-day old SD rat pups (males = 35; females = 35) were randomly assigned to four groups and administered treatments daily from postnatal (PND) 12-21: group 1-nutritive milk (NM), group 2-1 g/kg body mass ethanol (Eth), group 3-40 mg/kg body mass ZO and group 4 - NM+Eth+ZO. Terminal body mass, blood glucose concentration, lipid profile and hepatic antioxidant status were determined. Zingerone and ethanol had no effect on pups’ growth performance, blood glucose, total cholesterol, HDL- and LDL-cholesterol and hepatic thiobarbituric acid (TBARs), superoxide dismutase and catalase concentrations (p > 0.05). Ethanol decreased plasma triglyceride concentration in female rat pups (p = 0.04) but increased hepatic cytochrome P450E21 (CYP2E1) and decreased total glutathione (tGSH) concentration in male rat pups (p < 0.05). Zingerone increased tGSH in male rat pups (p = 0.003). A combination of ZO and ethanol increased (p = 0.047) hepatic CP2E1 concentration in male rat pups compared to control but had no effect (p = 0.717) on tGSH concentration. Neonatal orally administered ethanol induced hepatic oxidative stress which ZO, administered during the suckling period, failed to protect against. In experiment II, 123 SD rat pups (males = 60; females = 63) were administered the same neonatal interventions as in experiment I but from PDN22 they were grown to adolescence (PND45) with ad libitum access to normal rat chow and tap water. From PND 46-100, rats from each of the four neonatal groups were divided into two subgroups: subgroup I had tap water and subgroup II had ethanol solution as drinking fluids, for eight weeks. Body mass, feed, fluid and caloric intake were measured. Blood glucose concentration, plasma alanine transaminase and aspartate transaminase (ALT and AST) activities, adiponectin (ADP), leptin (LEP) and insulin (INS), tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and cytochrome P4502E1 (CYP2E1) concentrations were measured. HOMA-IR was computed. Visceral fat mass, hepatic fat content and histomorphometry were assessed. Hepatic TBARs and mRNA expressions of peroxisome proliferator activator receptor-alpha (PPAR-α), sterol regulatory element binding protein 1c (SREBP1c), nuclear factor kappa beta (NF-Kβ) and TNF-α were measured. Ethanol consumption in adulthood decreased feed and fluid intake but increased calorie intake and plasma CYP2E1 concentration (p < 0.05 vs control). It decreased blood glucose concentration of male rats (p = 0.026). A late single- and a double-alcohol hit had no effect on body and visceral fat mass of the rats (p > 0.05). Neonatal orally administered zingerone and ethanol and consumption of ethanol in adulthood had no effect on body mass, plasma lipid profile, adiponectin, leptin and insulin concentrations, HOMA-IR, AST and ALT activities, IL-6, TNF-α and hepatic TBARS and mRNA expression of NF-KB and TNF-α (p >0.05). A late single hit with ethanol increased hepatic fat content of male rats only (p = 0.014). A double and or late single ethanol hit increased liver fat content in female rats (p < 0.05). Both a late single and double ethanol hit downregulated PPAR-α but upregulated SREBP1c expression in male and female rats (p < 0.05) and it caused the development of large droplet macrosteatosis. A combination of neonatal orally administered ZO and a late single ethanol hit decreased visceral fat mass of female rats (p = 0.045 vs control) but it did not affect the blood glucose concentration of male rats (p > 0.05). Neonatal orally administered ZO with either a late single- or a double-ethanol hit caused hepatic macrosteatosis, but it had no effect on mRNA expression of PPAR-α of the rats (p > 0.05). However, neonatal orally administered ZO in combination with a late single ethanol hit did not affect SREBP1c expression of the rats but a combination of neonatal orally administered ZO with a double ethanol hit increased SREBP1c expression of female rats (p = 0.005). The responses of the rats to interventions showed sexual dimorphism: ethanol consumption in adulthood decreased blood glucose concentration of male rats only and an early single ethanol hit caused microsteatosis only in female rats. Zingerone protected male rats against ethanol-induced hepatic fat accumulation. It attenuated the ethanol-induced upregulation of hepatic SREPB1c expression in males but not in females. Ethanol (late single and/or double hit) downregulated the hepatic PPAR-α expression in the rats which was mitigated by ZO. Neonatal orally administered ZO attenuated the late single- and double-hit ethanol-induced macrosteatosis in the rats. Thus, neonatal orally administered ZO can potentially be used as a prophylactic agent against ethanol-induced hepatic lipid accumulation in males and steatosis in both males and females.Item The Experiences of Black Female Postgraduate Students With Mental Health During The Covid-19 Pandemic, 2019-2021, The Case of Witwatersrand University(University of the Witwatersrand, Johannesburg, 2024) Mashiane, Sphiwe; Bala, SamkeloThe COVID-19 global pandemic has compelled institutions of higher education to transition to emergency remote learning, leading many postgraduate students, both nationally and internationally, to begin their studies online. Research has shown the need for universities to support the transition from undergraduate to postgraduate as this is a major transition into academia. Research has also revealed that the struggle with mental health has increased with this transition and additionally with the COVID-19 pandemic, however, there is a lack of research investigating the experiences of Black females in the academic space and their experiences with mental health. Thus, this study aims to understand the experiences of Black female postgraduate students with mental health during the spread of COVID-19, 2019-2021. The research approach used for this study was the qualitative approach as it was the most appropriate in seeking to understand the experiences of a unique group such as a Black female postgraduate. A case study design was employed, and the experiences shared were explored through the lens of the intersectionality theory and the research was grounded by the interpretivist paradigm. The sample was drawn from the population of students from Witwatersrand University and the sample consisted of eight (8) participants. The method of data collection was computer-mediated interviews which were interpreted using a five-phase thematic analysis. The participants' responses revealed that although all eight participants experienced challenges with their mental health sharing symptoms associated with anxiety, stress, depression, and loneliness, only two participants used the psychosocial services offered by the university. The reasons for not seeking help from the university psychosocial services included fear of the unknown, services feeling unreachable, stigma and fear of not being assisted immediately. The most shared reason for not seeking help however was participants not perceiving the need to seek help. Participants, therefore, opted for coping mechanisms such as sleeping, partying, and using substances and most participants turned to their spirituality. The study, therefore, made recommendations for campus psychosocial services to employ more mental health practitioners such that there is education about mental health and the services offered.Item Neurocognitive Rehabilitation for an Adolescent HIV Population: The Case of Sustained Attention(University of the Witwatersrand, Johannesburg, 2024) Zondo, SizweThe Human Immunodeficiency Virus (HIV) continues to be a significant disease burden. In terms of neurocognitive health, HIV crosses the blood-brain barrier, resulting in neuronal dysregulation and compromised neurocognition. Of further import, antiretroviral drugs are indicated to have limited permeability in the central nervous system and do not reverse compromised neurocognition, sequent HIV neuroinvasion. The objectives of the study were to investigate the efficacy of HIV cognitive rehabilitation therapy (HIV-CRT) in adolescent HIV. The first aim was to investigate the evidence for the cognitive rehabilitation of HIV in adolescent and geriatric samples, sequent neuroHIV. This investigation resulted in the publication of a meta-analysis detailing the efficacy of attention remediation in neuroHIV. The second aim was to examine the efficacy of fNIRS neuroimaging in measuring hemodynamic responses in the prefrontal cortex in adolescents neuroHIV. This investigation resulted in the publication of an article detailing the efficacy of fNIRS in detailing changes in oxygenated haemoglobin in adolescents living with neuroHIV. The third aim was to pair fNIRS optical neuroimaging with behavioural data to investigate changes associated with brain training at a cortical and behavioural level. The execution of the above aim resulted in the publication of an article detailing the procedures and methods to achieve the enquiry. The fourth article, under review, details findings related to neural efficiency and attention training. The final manuscript, under preparation, details functional connectivity outcomes related to attention training. To enable the analysis of the published articles, an initial cohort of 42 adolescents (mean age = 17.28) living with HIV participated in the study. Following attrition, the sample was reduced to 26 participants. Thirteen participants were assigned to the treatment group (n = 13; mean age = 16; SD = 1.2), which received cognitive rehabilitation to remediate attention. Thirteen children acted as controls (mean age = 17; SD = 1.3). Pre- and post-intervention data were analysed using behavioural and optical imaging data. 5 Findings indicated that HIV-CRT (attention) is associated with decreased oxygenated haemoglobin (HbO) and increased functional connectivity in the Central Executive Network (CEN). Contrary to expectation, HIV-CRT was associated with minimal behavioural gains, as indicated by neuropsychological assessments. Taken together, findings seem to suggest that in adolescent neuroHIV, customised HIV-CRT promotes cortical efficiency. However, brain training does not translate to immediate behavioural improvements at post-assessment. Summarily, findings suggest that cortical plasticity may precede near-and-far cognitive transfer gain in adolescents neuroHIV.Item Career adaptability, occupational identity, and psychologica well-being after a career change during the covid-19 pandemic(University of the Witwatersrand, Johannesburg, 2024) Kutu, Siyamthanda; Donald, FionaOBJECTIVE: This study aims to explore the relationship between career adaptability, occupational identity, and Psychological Well-being at Work in South African employees who experienced career change during the COVID-19 pandemic. The study is framed within the Career Construction Theory where the pandemic is contextualised as a career shock. METHODS: Employing a quantitative approach, this study adopts a correlational, non-experimental, cross-sectional research design. Purposive sampling, including criterion-based and snowball sampling techniques, was utilized to recruit participants. The sample comprised 62 South African employees who experienced career changes between 2020 and 2022 due to the pandemic's impact on the labour market. Data w as collected through structured online questionnaires, incorporating validated scales. Ethical considerations were addressed, ensuring informed consent, confidentiality, and minimal harm to participants. RESULTS: Regression analysis revealed significant positive relationships between career adaptability, occupational identity, and Psychological Well-being at Work. Specifically, both career adaptability and occupational identity emerged as strong predictors of Psychological Well-being at Work among the participants. Descriptive statistics provided insights into the sample characteristics, indicating a diverse range of career change experiences during the pandemic. The study under scores the importance of fostering adaptability and building a robust occupational identity to enhance employees' psychological well-being amidst career transitions, particularly in times of crisis like COVID-19.Item The perceptions of social workers on the implementation of the Occupation Specific Dispensation policy (OSD) within the Department of Social Development in the Johannesburg Region(University of the Witwatersrand, Johannesburg, 2020) Mathebula, Sipho Sol; Masinga, PoppyThe Occupation Specific Dispensation (0SD) policy was introduced in the public service for social workers in 2009 as a strategy to recruit and retain social workers with the introduction of new salary scales, career pathing, pay and grade progression and recognition of appropriate experience. The perceptions of social workers on the implementation of the OSD policy have not been established and this lack of knowledge leaves a gap in understanding the perceived impact this policy has had on social workers. The aim of the study was to explore the perceptions of social workers on the implementation of the Occupation Specific Dispensation policy within the Department of Social Development in the Johannesburg Region. Since implementation of the policy, there has been research studies conducted on the outcomes of the OSD policy within the public health sector yet no studies have been conduct that focus on the challenges encountered by social workers in the implementation of the policy. The study utilised the qualitative research approach which was exploratory and descriptive in nature. The collective case study design was adopted. A sample of ten social workers and three key informants were selected using purposive sampling. Data was collected using semi-structured interviews and analysed using thematic content analysis. The key finding was that the OSD policy was not effective in recruitment since it is rigid and inflexible. Another concern raised was the long period it took to move from one occupational level to the next resulting in a demotivated and demoralised workforce. The study also found that there was management bias in the implementation of the performance management and development system. The study contributes to our understanding of the perceptions about the unintended consequences of the OSD policy and how these are perceived to have impacted negatively on the recruitment and retention of social workers.Item People’s Dignity is at stake: The Ambulance Availability Crisis in Lusikisiki, Ingquza Hill Local Municipality(University of the Witwatersrand, Johannesburg, 2024) Bolitina, SinovuyoAccess to healthcare is and remains a challenge globally. In South Africa, the limited ambulance availability crisis is an example of this. The people affected the most rely on public healthcare in remote and rural areas, such as the small town of Lusikisiki in the Eastern Cape Province. This study sought to investigate the research question, “How does the limited ambulance availability impact access to public healthcare for the people of Lusikisiki in the Ingquza Hill Local Municipality?”. I adopted a qualitative research approach and interviewed twenty participants identified through purposive and snowball sampling techniques. Limited ambulance availability inhibits the people of Lusikisiki from accessing healthcare. This crisis exists and impacts clusters of communities already facing socioeconomic, political, and geographical issues. These factors are at play and impact people’s day-to-day lives. Recommendations entail implementing more strategies and policies, looking at a more holistic approach, and examining this crisis from a social and health context perspective to overcome healthcare access barriers; thereby ensuring access and the health and well-being of everyone.Item Development of an interprofessional education and collaborative practice curriculum for health science students at Sefako Makgatho Health Sciences University(University of the Witwatersrand, Johannesburg, 2023-09) Pitout, Susara Johanna Susanna; Barnard-Ashton, Paula; Adams, Fasloen; du Toit, Sanetta Henrietta JohannaA South African university required a contextually relevant, Interprofessional Education and Collaborative Practice (IPECP) curriculum. The study aimed to develop and validate an IPECP curriculum for health sciences students at Sefako Makgatho Health Sciences University (SMU). Planning the IPECP curriculum necessitated both a robust theoretical foundation and pragmatic problem-solving and comprised three phases. Phase I, the situational analysis included a scoping review of global peer-reviewed literature, focus groups with students and lecturers, and a university-wide needs survey. Brookfield’s lenses of critical reflection and reflexivity condensed results of the situational analysis into factors guiding curriculum planning. Phase II included a curriculum map analysis of profession-specific curricula of the eleven professions: occupational therapy, physiotherapy, speech language pathology and audiology, human nutrition and dietetics, nursing, medicine, radiography, pharmacy, dentistry, dental therapy, and oral hygiene. The curriculum mapping involved consultation with professions’ representatives in combination with information extracted from LOOOP, an electronic curriculum mapping programme. The analysis identified the gaps in addressing interprofessional collaboration core-competencies and highlighted common topics, in the professions’ specific curricula. From the curriculum foundation laid by Phase I and II, an IPECP curriculum framework and design principles were conceptualised using a Curriculum Development Research design. In Phase III, the proposed SMU-IPECP curriculum and accompanying design principles were refined during iterative stages of design, development, testing and revision. Internal and external participants validated the curriculum by rating the relevance, consistency, practicality, and feasibility of the four-year, longitudinal curriculum. A modified Delphi guided consensus on the design principles. The curriculum escalated interprofessional role development from mere exposure to immersion, striving for competent representation in research, ethics and Primary Health care. The build-up followed a trajectory from a professional individualised role in the team, to students fulfilling a dual identity of professional and an interprofessional practice-ready practitioner, who practices in an evidence-based collaborative way as a primary health care advocate, in their final year. The curriculum validation highlighted affordances and constraints for future implementation. During validation, participants agreed on the design and commended the proposed IPECP curriculum. Although the curriculum was planned for a specific university, the theoretical design principles developed through this research process could potentially be customised to fit similar university contexts.Item Psychological Well-Being and South African Socio- Economic Stressors: The moderating role of Leaders creating Hope(University of the Witwatersrand, Johannesburg, 2024) Aysen, Savannah; Milner, KarenThe current research study explored whether leaders creating hope in their employees moderates the relationship between South African socio-economic stressors and employee psychological well-being. Existing literature indicates that stressors have dire implications for the well-being of employees and that psychological capital is a meaningful resource to elevate deteriorating well-being (Slone et al., 1999; Charles et al., 2013). Moreover, research reveals the potential of leaders to create hope within their organisations which may aid in elevating deteriorating well-being levels (Yukl, 1998; Helland and Winston, 2005). Accordingly, this research aimed to explore whether leaders creating hope would moderate the relationship between South African socio-economic stressors and psychological well-being. This study utilised a quantitative non-experimental cross-sectional research design to explore the statistical relationships between South African socio-economic stressors, psychological well-being and leaders creating hope. Data was collected through an online self-report questionnaire (N=130). The questionnaire contained a self-developed demographic questionnaire, an adapted South African socio-economic stressors scale, the Psychological General Well-Being Index, and the adapted Leaders Creating Hope scale. Results of the study indicated that both South African socio-economic stressors and leaders creating hope were correlated with psychological well-being, and a multiple regression analysis revealed that both South African socio-economic stressors and leaders creating hope are predictors of psychological well-being within the sample. However, even though leaders creating hope was found to have a positive effect on psychological well-being it did not have a moderating effect on the relationship between South African socio-economic stressors and psychological well-being.Item Exploring older adult narratives of living with a depressed parent(University of the Witwatersrand, Johannesburg, 2024) Dzenga, Rachel; Canham, HugoResearch on children of parents living with a mental illness is prevalent in developed countries and has shown that parental depression is linked to a higher risk of adverse outcomes for children. However, less research exists that focuses on older adult narratives, specifically regarding the lived experiences of growing up with a depressed parent. Therefore, this study provided a deeper exploration of older adults reflecting on their childhoods and highlighted the role that narrative hindsight has on the relationships between depressed parents and children. Exploring the narratives of people who grew up with a parent with a depressive disorder was the core interest of this study. Convenience and snowball sampling was used, and seven participants over the age of 60 years in South Africa were interviewed. Narrative theory was used as both a conceptual framework and a methodology, and narrative analysis was used to analyse data from the semi-structured interviews. The findings of the study suggest that the lived experiences of growing up with a depressed parent alter family dynamics and roles in the home, creating parentification in childhood, feelings of unpredictability, chaos, and uncertainty in the home environment. The role of narrative hindsight illuminated ambivalent feelings towards their depressed parents and revealed a significant influence on their own parenting decisions as adults, such as choosing not to have children. Beyond the immediate home environment, social factors such as stigma, institutionalisation and additional support arose as significant factors in the accounts of participants. The study explored the depth of the human experience in the participants’ ambivalence, meaning making, and social context growing up with a depressed parent. Interviewing older adults highlighted the significance of narrative hindsight and its role in understanding how temporality and nostalgia can illuminate the narrative arc between parent and child. Overall, the study illustrated the need for further research in South Africa on older adult narratives that could possibly enrich the knowledge of health practitioners, educators and researchers about the lived experiences of growing up with a depressed parent, assisting with family-based interventions based on a deeper understanding of the effects of parental mental illness over decades.