School of Clinical Medicine (ETDs)
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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 A retrospective study on the outcomes of peripartum hysterectomies for puerperal sepsis at Chris Hani Baragwanath Academic Hospital(University of the Witwatersrand, Johannesburg, 2024) Olusola, Esther; Naidoo, PoovangelaBackground: Puerperal sepsis is a significant cause of maternal morbidity and mortality, especially in developing countries. Hysterectomy is often performed as a measure of source control for severe uterine infections when conservative treatment fails. The aim of this retrospective study was to examine the outcomes of peripartum hysterectomies performed for puerperal sepsis at Chris Hani Baragwanath Academic Hospital, Johannesburg, South Africa. Methods: A retrospective cross-sectional study was conducted between 1 January and 31 December 2019, on all women who underwent hysterectomies for puerperal sepsis. Data pertaining to demographics, surgical characteristics, microbiological cultures, organ dysfunction scores, and histopathological findings, were extracted from medical records. Women with miscarriages or pregnancies less than 24 weeks’ gestation were excluded. Statistical analysis included descriptive methods and comparative tests using Stata 15.0 software. Organ dysfunction scores were calculated using MODS, SOFA, and qSOFA systems. Ethical approval was obtained prior to conduction of the study. Results: During the study period, 33 hysterectomies were performed for puerperal sepsis, representing 0.17% of the 18,458 deliveries at the hospital. The median age of women was 28 years of age with a median gestational age at delivery of 38 weeks. The majority (88%) underwent total abdominal hysterectomies, while 12% had subtotal hysterectomies. Eighty eight percent of women underwent caesarean section for a fetal distress. The most common organisms cultured in intra-abdominal fluid were Acinetobacter baumannii (26%), Escherichia coli (19%), Klebsiella species (14%) and Enterococcus faecalis (14%). A. baumannii was the predominant pathogen in all four culture mediums. The most common antibiotics used in this hospital for treatment were resistant against most organisms. Women with higher MODS and SOFA scores predominantly cultured resistant organisms. A. baumannii was strongly associated with worse outcomes. Two women (6%) died due to complications of ongoing sepsis. Histological examination revealed that surgeons often underestimated the extent of necrosis (30%) and presence of pus (44%), highlighting the importance of histopathological evaluation for accurate diagnosis and management. Conclusion: This study highlights the rising antibiotic resistance which complicates treatment and emphasises the need for revision of antibiotic stewardship in puerperal sepsis management. Women with higher MODS and SOFA scores predominantly cultured resistant organisms. Further research is required to explore improving surgical recognition of uterine sepsis and whether a total abdominal hysterectomy is actually superior to a subtotal hysterectomy in women with puerperal sepsis.Item Patterns of HIV Resistance in Children Attending an Antiretroviral Clinic in Soweto, South Africa: A Case-Control Study(University of the Witwatersrand, Johannesburg, 2023) Vilakazi, Zinhle; Moore, David Paul; Sipambo, Nosisa; Steegen, KimBackground: Exposure to suboptimal serum levels of antiretrovirals (ARVs) places resistance pressure on circulating human immunodeficiency virus (HIV), with consequent emergence of resistance. HIV resistance leads to treatment failure and adverse outcomes. We explored factors associated with the emergence of ARV resistance in children living with HIV (CLWH) attending a treatment clinic in Soweto. Methods: We reviewed the clinical and laboratory characteristics, and factors associated with ARV resistance in children aged 0 to 15 years of age that were treated at the clinic from 01 January 2011 through 31 December 2020. The Stanford HIV drug resistance database was used to identify HIV drug resistance mutations and generate resistance profiles. Characteristics of children that underwent drug resistance testing (DRT) were compared to those of children who remained virologically suppressed on fist-line ARVs. Results: During the study period, 7,029 children attended the clinic of which 425 (6.0%) underwent DRT (cases) and 953 (13.6%) remained suppressed on first-line ARVs (controls). The resistance dataset included 431 resistance tests that were done in 425 children and adolescents that were eligible for the study. Non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations accounted for 50.8% of all mutations, followed by nucleoside reverse transcriptase inhibitor (NRTI) mutations (44.5%) and protease inhibitor (PI) mutations (4.6%). Cases were significantly older at ARV initiation (81.6 vs 45.2 months), had a higher prevalence of ever being diagnosed with tuberculosis (33.2% vs 27.4%), ever being orphaned (57.6% vs 50.6%) and ever experiencing severe acute malnutrition (SAM) (19.8% vs 11.7%). In all modelling approaches, SAM was consistently associated with ARV resistance adjusted odds ratios (aOR) ranging from 3.548 (95% confidence interval (CI) 1.979-6.359) to 6.383 (95% CI, 3.811-10.690)). Increasing baseline CD4 percentage was associated with significantly lower adjusted odds of case-status aOR ranging from 0.971 (95% CI, 0.953-0.989) to 0.951 (95% CI, 0.931-0.972)). Seventeen (5.6%) cases died, compared to two (0.3%) controls; P<0.001. Conclusions: Tenuous nutritional status was consistently and significantly associated with the requirement for DRT in this cohort of children and adolescents. Conversely, higher baseline CD4 percentage was associated with control status. Early ARV initiation, to preserve immunological status, and nutritional support throughout the course of clinic attendance may limit the emergence of drug resistance in CLWH.Item Voiding cystourethrography in the renal pre-transplantation workup: an essential investigation?(University of the Witwatersrand, Johannesburg, 2022-10) Sofianos, Zelia; Rajkumar, Leisha; Lucas, SusanINTRODUCTION: Due to resource constraints in the South African public healthcare sector, patients with End-Stage Renal Disease (ESRD) are eligible for renal replacement therapy only if they are also found to be eligible for renal transplant. AIM: The aim of this study is to document Voiding Cystourethrogram (VCUG) findings in potential renal transplant candidates to assess the contribution of the VCUG as a standard investigation in the renal transplant workup. METHODS: Of the patients who underwent VCUG in Klerksdorp/Tshepong Hospital Complex (North West province, South Africa) from 1 January 2019 to 31 March 2020, 85 patients were included in the study and their VCUG findings retrospectively analysed. RESULTS: The mean age was 40.0 years (range 21-62 years), with males constituting 57.7% of patients and females 42.3%. Lower urinary tract abnormalities were identified in 24.7% of patients, some of whom had more than one abnormality. Of the total abnormalities, VUR (vesicoureteral reflux) accounted for 15.3%, bladder diverticula for 5.9%, urethral strictures for 3.5% and a significant post-void residual volume for 4.7%. No comorbidities were found to have a statistically significant association with the presence of VCUG abnormalities. CONCLUSIONS: To ensure that patients with End-Stage Renal Disease are adequately prepared for renal dialysis and potential renal transplant, and that their comorbidities and lower urinary tract are optimised should abnormalities be identified on VCUG, the VCUG remains an essential investigation in the renal transplant workup.Item Emergency Department Turnover Intention: Are Job Satisfaction and Burnout Really the Main Culprits?(University of the Witwatersrand, Johannesburg, 2022-11) Jonker, Yvonne Denise; Motara, Feroza; Moolla, MuhammedBackground: Patient presentations to emergency departments (ED) keep increasing. High staff turnover is detrimental to the healthcare worker (HCW), the organisation and the patient. While high levels of burnout (BO) and low levels of job satisfaction (JS) lead to a higher intention to leave (ItL), there are other factors affecting the ItL that need to be evaluated. Objective: To determine the levels of BO, JS and ItL, including when, where and why HCWs want to leave in order to find ways to reduce staff turnover. Methods: This was a prospective observational cross-sectional study conducted in two tertiary-level EDs in Johannesburg, South Africa namely Chris Hani Baragwanath Academic Hospital (CHBAH) and Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). Doctors and nurses were invited to complete self-administered questionnaires between 24 November 2020 and 24 March 2021. After analysis the results for doctors and nurses and the two units were compared in order to bring understanding to the different facets affecting staff turnover. Results: A total of 78 respondents (66% of doctors and 58% of nurses) completed questionnaires and were included for analysis. According to the Copenhagen Burnout Inventory 79% of CHBAH doctors, 62% of CHBAH nurses, 79% of CMJAH doctors and 84% of CMJAH nurses suffered from severe personal burnout, while 68% of CHBAH doctors, 62% of CHBAH nurses, 95% of CMJAH doctors and 68% of CMJAH nurses suffered from severe work-related BO and 42% for CHBAH doctors, 24% of CHBAH nurses, 47% of CMJAH doctors and 32% of CMJAH nurses had severe patient-related burnout. Doctors had significantly higher patient-related burnout (p=0.012). JS was average for all staff but nurses were significantly less satisfied (p=0.003). While 42% of staff intended to leave within a year, of which half wanted to leave as soon as possible, a total of 73 % wanted to leave within 5 years. CMJAH staff had higher levels of BO, lower levels of JS and higher levels of ItL. Higher levels of BO and lower levels of JS increased the ItL. The main reasons for leaving were career-related. Conclusion: Burnout levels were higher than similar populations before and during the Covid-19 pandemic, while job satisfaction levels were average. Although burnout and job satisfaction affected intention to leave, the main reasons for wanting to leave were career-related indicating that even when work conditions and burnout could be addressed successfully, the turnover of staff in tertiary level EDs may remain high.Item Analysis of Orthopaedic Injuries in Polytrauma Patients at Charlotte Maxeke Johannesburg Academic Hospital(University of the Witwatersrand, Johannesburg, 2022) Laney, Wezley; Naicker, Dharshen; Milner, BrendaBackground: Traumatic injuries represent a significant burden globally, accounting for ten percent of the global burden of disease. In South Africa we commonly see patients who have sustained major trauma, often with multiple injuries. This significant burden of trauma necessitates the demand for rapid diagnostic assessment of injuries for appropriate therapeutic intervention. A whole body computed tomography (CT pan scan) allows for a rapid multisystem injury diagnosis of trauma patients. There is a scarcity of literature evaluating the extent of orthopaedic injuries in polytrauma patients. Study Aim: The aim of the study was to evaluate the local epidemiology of orthopaedic injuries in polytrauma patients who have undergone a CT pan scan. Methods: A retrospective, observational analysis, based at Charlotte Maxeke Johannesburg Academic Hospital, was done of polytrauma patients who underwent a CT pan scan, during a 2-year period from 01/01/2018 – 31/12/2019. A database was compiled by accessing the picture archiving and communication system for CT reports. The qualitative data was reported using frequencies and percentages. Categorical variables were analysed using the Chi-squared test (or Fisher’s exact test). Results: Over the two-year study period a total of 296 polytrauma patients had a reported CT pan scan performed. Of these, 85% were male and 15% were female with a median age of 33 years. The most common mechanism of injury was motor vehicle accidents (33.1%). The prevalence of orthopaedic injuries in polytrauma patients was 53.3%. A total of 1012 injuries were found. One hundred and ninety-six (196) spinal fractures were detected; a total of 137 pelvic/sacral fractures, 101 long bone fractures with 75% lower limbs and 25% were upper limb fractures. The most common non-orthopaedic injury sustained was a chest injury. The most common combination of orthopaedic and non-orthopaedic injuries identified in the study was a chest injury with an associated pelvic/sacral fracture secondary to a PVA. Interpersonal and intentional injuries were significantly associated with a higher risk of thoracic spine fractures (RR 1.8, CI 1.1-2.9). Road traffic accidents were significantly associated with a higher risk of scapular/clavicular fractures (RR 2.0, CI 1.2-3.5) and a higher risk of tibial/fibula fractures (RR 3.5, CI 1.2-10.3) Conclusion: The majority of polytrauma patients seen at CMJAH were young males, who sustained injuries during road traffic accidents. Fractures accounted for 94% of all orthopaedic injuries. The most common orthopaedic injury detected in our cohort, overall, was a spinal fracture, most commonly involving the cervical spine. A patient involved in a road traffic accident is 3.5 times more likely to sustain a tibia/fibular fracture as opposed to any other fracture. The most common non-orthopaedic injury sustained was a chest injury. Importantly, 1 in 4 of these patients sustained an associated cervical spine injury and 1 in 3 a pelvic injury, similarly with head injuries. The most common combination of injuries is a chest injury with an associated pelvic/sacral fracture secondary to a pedestrian vehicle accident. The findings highlight the significant burden of orthopaedic injuries in polytrauma patients. In addition, the findings of this study, highlight injury patterns that should be anticipated in polytrauma patients.Item Maternal death at Leratong Regional Hospital: a six-year retrospective review, South Africa(University of the Witwatersrand, Johannesburg, 2021-11) Motau, Tumelo Ngaka; Chauke, LawrenceBackground: The aim of the study was to systematically examine the main causes of maternal deaths and contributing factors at Leratong Regional Hospital in order to recommend strategies that can assist in reducing maternal mortality at this level of healthcare. Objectives: The objectives of the study were to: determine the institutional maternal mortality rate at Leratong Regional Hospital between 2012 to 2017, compare the trend (year on year) in the iMMR over the study period, describe the profile of women who died during the period under study, describe the clinical and surgical management of the women who died, and to determine the leading causes of maternal deaths, contributing factors and avoidable factors. Methods: A hospital based retrospective study based on patient clinical records at Leratong hospital. It included all the maternal deaths that occurred at Leratong Regional Hospital during the six-year study period (2012-2017). Results: There was a total of 78 maternal deaths with 32441 live births giving the MMR of 240 per 100 000 live births. However only 74 files could be analysed. The results showed that there was a rise in the maternal mortality rate over a six years period. The majority (70, 94.5%) of the women who died were African, aged between 20-35 years (56, 76%), multigravida (54,73%) with a parity of three or more (23, 31%). Obstetric haemorrhage was the leading cause of maternal death particularly postpartum haemorrhage (11.14%) followed by non-pregnancy related infections, sepsis and eclampsia. Conclusion: Maternal mortality has decreased according to recent confidential enquiry into maternal death in South Africa (2017-2019) However our study did not demonstrate a decline but rather an increase in the maternal mortality rate at Leratong. It showed that most of the maternal deaths were avoidable and the need for urgent interventions in terms of education, improving access to health care facilities, intensifying health care worker skills training and better transport systems between health care facilities is important.Item A Retrospective Review of Bladder Cancer at Charlotte Maxeke Johannesburg Academic Hospital-University of The Witwatersrand - (2010–2020)(University of the Witwatersrand, Johannesburg, 2023-08) Oliver, Trenton Luke; Ayeni, Oluwatosin; Hugo, MiaIntroduction: Bladder cancer is among the most common urological cancers and the leading cause of cancer mortality worldwide. It is particularly prevalent in High-Income Countries (HICs), although its incidence is rising in Low-and-middle -income countries (LMICs). This review describes the profile, clinical presentation, and management of our institution's bladder cancer patients. Method: A retrospective review of patients aged 18 years and above who were diagnosed with bladder cancer and managed at the Radiation Oncology department of Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) from January 2010 to December 2020. Data were collected on demographics, risk factors, clinic-pathological features, and specific therapies received by these patients. A comparison was made between patients presenting with squamous cell carcinoma and translational cell carcinoma of the bladder. Results: Among 115 patients, the median age ± standard deviation was 60.7 ± 14.9, and 60.9% were males with a male-to-female ratio of 1.6:1. Few patients (4.4%) had a history of schistosomiasis, and 47.8% had a history of smoking. Tumour histology included transitional cell carcinoma (TCC) in 78 (67.8%), squamous cell carcinoma (SCC) in 31 (27.0%), and atypical tumour in 6 (5.2%). Most patients presented with Muscle-Invasive Bladder Cancer (MIBC) (61 (53.0%)) followed by Metastatic Urothelial Cancer (MUC) (n=52, 45.0%), while the remaining 2.0% (n=2) had Non-Muscle Invasive Bladder Cancer (NMIBC). More than half of the patients (59.1% n=68) had palliative treatment, 26 (22.6%) had radical treatment, and 21 (18.3%) patients did not receive radiotherapy. Patients who presented with TCC were more likely to be older (odd ratio (OR): 1.03, 95% Confidence Interval (CI): 1.01–1.06, p=0.029), male (OR: 2.60, 95% CI:1.10–6.04, p=0.030), predominantly of the black population, but white patients are four times more likely to present with TCC than SCC (OR:4.22, 95% CI: 1.43–12.48, p=0.009). Conclusion: The prevalence of TCC is still higher in our centre compared to SCC. Although the burden of bladder cancer is highest in HICs, with increasing exposure to risk factors, a shift is gradually experienced in LMICs.Item Outcomes of Reconstructive Hip Surgery in Gross Motor Function Classification System Level IV and V Cerebral Palsy Patients(University of the Witwatersrand, Johannesburg, 2023-08) Tink, Scott Colin John; Bischof, Faith M.; Robertson, Anthony J.F.Background: Varying degrees of hip displacement have been observed in up to 75% of paediatric patients with cerebral palsy (CP). Conflicting data exists regarding the incidence of significant hip pain associated with displacement, and whether surgical intervention benefits such patients with known high recurrence and complication rates. There is a paucity of evidence regarding the outcomes of reconstructive hip surgery in an African environment. Study objective: To establish medium-term functional and radiological outcomes of reconstructive hip surgery, in a cohort of non-ambulatory patients with CP, within an African context. Methods: This was a single centre, 5-year, retrospective study, reviewing non-ambulant Gross Motor Function Classification System (GMFCS) Level IV and V patients who underwent reconstructive hip surgery, between 2013 – 2017. Each primary caregiver completed a caretaker questionnaire. Pre- versus post-operative sitting function, hip pain frequency and intensity, activities of daily living (ADL’s), radiological outcomes and complications were explored. Descriptive statistics, Wilcoxon signed rank and Spearman Rho non-parametric tests were used to analyse and present the findings. Results: Forty-one participants were included, who underwent varus derotation osteotomy (VDRO) and adductor tenotomy, performed on 75 hips. Mean age at surgery was 8.7 years (3.3 – 16.3 years), and mean follow up was 6.3 years, (3.2 – 8.4 years). Surgery was bilateral in 34 cases. Ease of changing diapers and maintaining perineal hygiene was the only ADL to have improved (p=0.027). No improvement in sitting ability was noted. Significant hip pain decreased from 88% pre-operatively, to 32% post-operatively. (p<0.001). Using Reimer’s migration percentage (MP), both groups demonstrated significant improvement in hip containment (p=0.029). GMFCS Level V patients experienced more complications (60%), compared to Level IV patients. Conclusion: Natural sequalae of CP renders these patients susceptible to painful hip instability. Although most patients in this study experienced improved hip abduction with increased ease of perineal hygiene, improved pain relief and better post-operative hip enlocation, the high incidence of complications emphasizes the importance of close follow up of patients living with CP.Item Histopathological Spectrum of Conjunctival Lesions at St John Eye Hospital(University of the Witwatersrand, Johannesburg, 2023-07) Mofokeng, Thabiso; Welsh, NicoleBackground: Various non-invasive modalities have been described in diagnosing conjunctival lesions but histology remains the gold standard. Shortages in ophthalmology services and pathology laboratories in non-urban areas is one of the main reasons for delayed presentation and appropriate treatment in sub-Saharan Africa. The purpose of this study is to determine the spectrum of histopathologic findings in conjunctival lesions from patients at St John Eye Hospital (SJEH). Materials and Methods: Data of patients who underwent conjunctival surgical biopsies was retrieved from the main theatre register of SJEH for a period of 3 years, starting from 1st November 2016 to 31st October 2019. This data was used to retrieve histology reports from National Health Laboratory Services (NHLS). Results: A total of 679 patient records were retrieved from the theatre register, only 585 histology reports from 584 patients could be analysed. There were 305 benign lesions with pterygia making up most of the benign lesions with a total of 249 (42.56%). A total of 174 premalignant lesions were recorded with severe ocular surface squamous neoplasia (OSSN) making up the bulk of premalignant lesions, 147/174(84.48%). Squamous cell carcinoma (SCC) was the main malignant lesion, 102 reported cases of a total 106 malignant lesions. The age ranged from 1 to 90 years with mean of 43.14 years. The patients were predominantly black, Caucasians constituted only 1%. The average age for SCC was 41.3 years, severe OSSN 43.6 and pterygia 46.3 years. Benign and premalignant lesions had a slightly higher predilection for females at 55.4% and 58.6% respectively. Males had a slightly higher predilection of malignancy at 54.7%. Conclusion: Pterygia are the most common excised benign conjunctival lesions and severe OSSN is the most common premalignant lesion excised at SJEH. SCC made up the bulk of conjunctival malignancies excised at SJEH. Pterygia, OSSN and SCC presents in a significantly younger age group when compared with reports from Europe, North and South America.