Masters Degrees (Epidemiology and Biostatistics)


Recent Submissions

Now showing 1 - 5 of 18
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    Translation and validation of the Shona version of the exercise benefits and barriers scale in Zimbabwean adult people living with HIV/AIDS : a cross-sectional study
    (Stellenbosch : Stellenbosch University, 2023-03) Dambi, Jermaine Matewu; Esterhuizen, Tonya; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Epidemiology and Biostatistics.
    ENGLISH SUMMARY: Objectives: Despite the widely known benefits of physical activity (PA), only 25% of people living with HIV (PLHIV) meet the WHO-recommended minimum PA levels. With the need to promote PA, there is a need to objectively measure PA, including understanding context-specific barriers, facilitators, and general awareness of the importance of PA. This study aimed to translate and validate the Shona version of the Exercise Benefits and Barriers Scale (EBBS) in Zimbabwean PLHIV. Design: cross-sectional study. Setting: Four (4/9) randomly selected polyclinics (primary healthcare facilities) in urban Harare, Zimbabwe. Participants: We recruited adult patients (aged ≥ 18 years) with a confirmed diagnosis of HIV. Participants had to be willing to provide informed consent, not acutely unwell and requiring emergency treatment, and proficient in the Shona language. Interventions: We used a forward-backwards translation method to translate the EBBS from English to Shona, a Zimbabwean native language. The alpha EBBS-Shona version was pilot tested on 10 PLHIV to assess the face validity, understandability and cultural appropriateness using semi-structured interviews. Thereafter, the EBBS was administered to 567 consecutively selected PLHIV. Results: Most participants were female (72.5%) and self-reported having secondary/high school education (78.8%), with a mean age of 39.9 (SD 12.1) years. The EBBS-Shona version yielded a four factor solution consisting of three benefits factors and one barrier factor against the originally postulated six-factor structure. The EBBS-Shona yielded α=0.85 and intraclass correlation coefficient= 0.86, demonstrating excellent reliability. Increased perception of exercise benefits was positively correlated with increased reports of physical activity, higher health-related quality of life and lower psychiatric morbidity; evidence for construct validity. Conclusions: This study demonstrates the validity and reliability of the EBBS-Shona version in Zimbabwean PLHIV. The EBBS-Shona version can be used for research and clinical purposes to glean data to inform the development, implementation, and evaluation of bespoke PA interventions for PLHIV. Strengths and limitations of this study: • Application of a robust translation and adaption methodology • Utilisation of both exploratory and confirmatory factor analysis for structural validation • Recruitment of a large sample size • Electronic data collection negating missing responses • Non-random, facility-based recruitment of study participants
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    Risk factors of neurodevelopmental delay in paediatric tuberculous meningitis
    (Stellenbosch : Stellenbosch University, 2022-04) Saal, Caro-lee; Solomons, Regan; Esterhuizen, Tonya; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Epidemiology and Biostatistics.
    ENGLISH SUMMARY: Objective: Neurodevelopmental delay in children is one of the long-term complications of tuberculous meningitis (TBM) with significant social, financial and scholastic implications. The objective of the study was to assess the risk factors in children with case-defined TBM that could predict neurodevelopmental delay at the conclusion of anti-tuberculous treatment, after 6 months in HIV non-infected and 9 months in HIV co-infected. Methods: We conducted a retrospective cohort study of all the children diagnosed with TBM at a large academic hospital in Cape Town, South Africa, over a 30-year period between 1985 and 2015. We assessed the relationship between demographic, clinical, laboratory and neuro-imaging characteristics, with cognitive impairment at conclusion of anti-tuberculous treatment. Results: A total of 327 patients were included. The median age on admission was 28 months (interquartile range(IQR) 15-47) with females accounting for 159 (48.6%) and males 168 (51.4%).Of included participants 170 (52%) were HIV negative. Younger age at diagnosis was more likely to have lower IQ levels. Patients were more likely to have lower IQ levels if they had decreased level of consciousness (LOC) (OR=3.30, 95% CI: 1.80-6.05); brainstem dysfunction (OR=2.39, 95% CI: 1.42-4.02); motor function impairment (OR=1.96, 95% CI:1.14-3.39) and infarcts (OR=2.60, 95% CI: 1.53-4.42). Those with positive CSF culture results were less likely to have lower IQ levels (OR=0.38, 95% CI: 0.20-0.75) Conclusion: This study demonstrated that demographic (age on admission) and clinical characteristics (decreased level of consciousness, impaired motor function, brainstem dysfunction, cerebral infarcts, negative cerebrospinal fluid (CSF) culture) were independent risk factors for lower IQ levels at treatment conclusion, in children with clinically-defined TBM.
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    A secondary analysis using individual patient data of two pragmatic cluster-randomized control trials evaluating 3 monthly and 6 monthly community-based multimonth dispensing of antiretroviral treatment in Southern Africa
    (Stellenbosch : Stellenbosch University, 2021-03) Lopes, John; Fatti, Geoffrey; Lombard, Carl J.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Epidemiology and Biostatistics.
    ENGLISH SUMMARY: Randomized evidence of the effectiveness of community-based multi-month dispensing (MMD) of antiretroviral treatment (ART) is lacking, particularly for 6 months MMD with only annual clinical consultations. Data from two cluster randomized trials (CRTs) were pooled to compare community-based MMD of ART versus non-inferior to standard-of-care facility-based MMD. Methods: Adult people living with HIV (PLHIV) stable on ART for ≥6 months with viral load suppression (VLS) at baseline was included. Community-based 3 monthly (3MC) and 6 monthly (6MC) ART refill dispensing were compared to control facility-based 3 monthly (3MF). Twelve months retention-in-care (primary outcome) was evaluated by intention-to-treat using individual-level regression analyses, with a prespecified non-inferiority margin of -3.25% risk difference (RD). Secondary outcomes evaluated after 12 months were; (1) retention within the study arm (2) VLS, (3) number of unscheduled facility visits, and after 18 months; (4) attrition in ART care. Results: Data pooling yielded a total of 10136 participants with relatively balanced characteristics across the arms, except for age and district. Retention after 12 months was noninferior in the adjusted analysis (3MC: RD=0.3, 95% CI: -0.8 to 1.4 vs 3MF, 6MC: RD=-0.2, 95 % CI: -1.4 to 1.0 vs 3MF). VLS was high (≥97.9%) with no differences between the arms, risk ratio (RR) of 1.0 for 3MC (95 % CI: 1.0 to 1.0, p=0.885) and 6MC (95 % CI: 1.0 to 1.0, p=0.186) compared to 3MF. The incidence rate ratio (IRR) for unscheduled visits showed no difference between 3MC (IRR=0.6, 95 % CI: 0.2 to 2.1, p=0.383) and 6MC (IRR=1.0, 95 % CI: 0.4 to 2.5, p=0.974) compared to 3MF. Participant attrition (0-18 months) for Zimbabwe showed no differences between the arms, facility location or healthcare level. Conclusion: Community-based MMD of ART at 3 and 6 monthly refills for PLHIV stable on ART is safe to scale-up, without increased unscheduled facility visits or compromise in VLS.
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    The impact of caring for a school-going visually impaired child in Cape Town, Western Cape on the home caregiver and the rest of the family – the health, socio-economic and psychological health burdens
    (Stellenbosch : Stellenbosch University, 2021-03) St. Jerry, Marlyse; Barnes, J. M. (Johanna Maria); Nyasule, Peter S; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Epidemiology and Biostatistics.
    ENGLISH SUMMARY : Background: Visually impaired (VI) children need additional care for daily tasks due to their diminished independent living skills (ILS). In learners in Special Educational Needs (LSEN) schools and specially-adapted mainstream schools, occupational therapy and trained assistants help to bridge the gap that diminished ILS pose to their education. However, in impoverished areas of the Cape Metropole, many families cannot afford trained caregivers in their homes. Typically a maternal figure fulfils the responsibilities of caring for the VI child as well as for the rest of the household; such a person then becomes the VI child’s primary home caregiver. Aims and Objectives: The main focus of the study was to determine the caregiving load and its impact on the caregiver's physical, mental and emotional well-being. Methods: The cross-sectional study used a questionnaire consisting of a self-designed questionnaire based on issues from literature on the subject and the validated Caregiver Strain Questionnaire – Short Form (CGSQ-SF). The CGSQ-SF provides qualitative data on the noticeable, emotional, and overall impact of caregiving. During prescheduled home interview sessions, the caregivers completed the questionnaires. The mixed research method used measurable data such as financial status and qualitative data, such as the emotional experiences associated with caring for a VI child. The University of Stellenbosch ethics committee (S13/03/049) and the Western Cape Education Department (20130704-13796) approved the study. Professor M. Kidd of the Centre for Statistical Services at the University of Stellenbosch carried out the statistical analyses, Mann-Whitney U tests and Kruskal-Wallis tests analysed the relationship of variables with CGSQ-SF scores. Results: Of the population of 320 VI learners from the only school for the VI in the Cape Metropole, 150 learners resided at home during the school term. According to the inclusion criteria, only 95 of the 150 home caregivers were eligible. The study obtained consent from 73 caregivers. The CGSQ-SF scoring showed that the majority of the 73 caregivers experienced moderate strain in terms of overall (55/73; 75.3%), objective (57/73; 78.1%) and subjective internalised caregiver strain (55/73; 75.3%). Elevated caregiver strain frequently occurred with these factors: financial difficulty; diminished ILS; and reluctance to spend time away from the VI child. Conclusion: All the caregivers experienced a considerable caregiving load and subsequently substantial caregiver strain level. All the participating households experienced both poverty and caring for a VI child. This bias in the design made it difficult to attribute what strainload was due to either of these variables. It was not possible to determine whether having a VI child increased the household’s strain compared to those who did not have a VI child. The confounding nature of the design made it challenging to unravel the relationship between poverty and caregiver strain due to the presence of a VI child. Qualitative information from the caregivers suggested that they did not view their child’s special needs as the only cause for the financial struggles they face and that their biggest concern was their child’s future as a disabled adult.
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    Influence of previous tuberculosis treatment on time to culture conversion for patients receiving a bedaquiline-containing regimen at Sizwe Tropical Disease Hospital, South Africa
    (Stellenbosch : Stellenbosch University, 2021-03) Saimen, Amashnee; Esterhuizen, Tonya; Padanilam, Xavier; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Epidemiology and Biostatistics.; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Global Health. Epidemiology and Biostatistics.
    ENGLISH SUMMARY : Tuberculosis remains one of the leading causes of death worldwide. There is a growing crisis concerning the number of drug resistant TB cases. New drug regimens were urgently needed to improve mortality and morbidity among drug resistant TB patients. Bedaqualine is a newly developed diarylquinoline with a unique mechanism of action. . Studies have reported varying time to culture conversion regarding RR/MDR-TB patients with history of previous TB treatment. The Rv0678 mutation found in patients with prior Rifampicin exposure has demonstrated a more than four-fold increase in the minimum inhibitory concentrations of Bedaquiline. Previously treated TB patients may be more likely to have higher bacterial load due to extensive parenchymal damage. This study will provide information on effective Bedaquiline treatment duration for those previously exposed to TB treatment. Aim: To determine whether previous exposure to TB treatment influences the time to culture conversion as compared to no previous TB treatment exposure in patients receiving a DR- TB regimen containing Bedaquiline. Primary Objective: To compare the time to culture conversion for previously treated and new DR-TB patients receiving the Bedaquiline containing regimen. Secondary Objectives: 1.To evaluate treatment regimens at time of culture conversion for previously treated andnew DR-TB patients 2.To compare the rate of relapse in previously treated and new DR-TB patients receivingthe Bedaquiline containing regimen. 3.To compare the duration of Bedaquiline therapy in previously treated and new DR-TBpatients 4.To establish the severity of disease of previously treated and new DR-TB patients. Setting and Study Population: The study will be conducted at Sizwe Tropical Disease Hospital in Gauteng Province. Sizwe Tropical Disease Hospital serves as a referral centre for complicated MDR/XDR-TB cases in Gauteng. Study Design: A retrospective cohort study will be undertaken for confirmed DR-TB patients who were initiated on DR-TB regimen containing Bedaquiline from April 2016 to March 2019. Inclusion Criteria: Bacteriologically confirmed DR-TB All patients receiving DR-TB Regimens containing Bedaquiline including new DR-TB with no previous history of TB treatment Documented culture conversion Variables: Culture Conversion; Time to culture conversion; Duration of Bedaquiline treatment Sampling Technique: The group sample sizes were determined to be 76 (Previous treatment group) and 304 (New treatment group), power of 80% with a level of significance of α 0.05. Time Frame: The study will be conducted from June 2020 to November2020.