Theses and Dissertations (Clinical Epidemiology)

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Effectiveness of pneumococcal vaccine in preventing hospital admissions for pneumonia among the elderly
(University of Pretoria, 2019) Girdler-Brown, Brendan V.; themofokengs@gmail.com; Rapetsoa, Maropeng Innocentia Kgomotso
Introduction Hospitalisations and prolonged hospital stays impose great economic burden especially at the present time when resources are limited. Community-acquired pneumonia (CAP) is a common and costly illness associated with considerable morbidity and mortality. Other than children, the elderly are the most vulnerable to CAP due to reduced immunity and comorbid chronic conditions. Streptococcus pneumoniae (S. pneumoniae) has been identified as the most common culprit encountered in cases of CAP with the incidence of CAP peaking during the annual influenza season. There is a known synergistic pathogenesis between the influenza virus and S. pneumoniae. Vaccination against invasive pneumococcal disease (IPD) is established in children. However, the burden of pneumonia has remained high in the elderly. This study sought to explore primarily the effectiveness of pneumococcal vaccination, as administered in a South African Medical scheme population, in the elderly who are aged 65 years and older; and secondly to explore the effectiveness of influenza vaccination in the same age group in preventing hospital admissions due to pneumonia (all causes). Methods The study population consisted of 34 068 beneficiaries of Medihelp medical aid scheme, and the outcome measures were investigated for years 2017/2018. The researcher has conducted a case-control study using cross-sectional secondary data with 1:1 matching. The sample size consisted of 800 pairs of case and control for primary and secondary exposures (pneumococcal vaccine and influenza vaccine, respectively). ICD-10 (International classification of diseases .10th revision) coding was used to identify study cases based on hospital admission claims and was matched for covariates age, sex and important comorbidities: ischaemic heart disease (IHD), chronic obstructive pulmonary disease (COPD), asthma and diabetes mellitus (DM). For the primary outcome, we adjusted for the use of influenza vaccine and for the secondary outcome, we adjusted for the use of pneumococcal vaccine. McNemar’s odds ratio (OR) and its 95% confidence interval (CI) was used to measure the association between vaccination and hospitalisation for CAP. Sensitivity analyses by means of propensity score matching (PSM) were also performed to estimate the OR. In addition, subgroup analyses were performed by estimating the odds ratios in participants who have used 23-valent pneumococcal polysaccharide vaccine (PPSV-23) and 13-valent pneumococcal conjugate vaccine (PCV-13) respectively for the primary exposure by PSM. Results All participants had claimed only one type of pneumococcal vaccine in this study. Vaccine uptake for pneumococcal vaccine and influenza vaccine in the study population were 0.9% and 16.6% respectively. For the primary exposure, 15 (1.9%) cases were exposed to pneumococcal vaccine compared to nine (1.1%) in controls with an OR of 1.67 (95% confidence interval (CI), 0.683 - 4.319) (P= 0.308). Propensity score matching revealed similar estimates, although closer to the null value, with OR of 1.05 (95% CI, 0.991 - 1.121) (P= 0.095). For the secondary exposure, 140 (17.5%) cases were exposed to influenza vaccination compared to 152 (19.0%) controls with an OR of 0.90 (95% CI, 0.683 - 1.178) with a (P= 0.460). Using PSM the OR was 0.99 (95% CI, 0.983 - 0.994) (P<0.001). Conclusions In order to enhance the vaccine effectiveness (VE) of pneumococcal vaccine, it is recommended that sequential vaccination with a dose of PCV-13 to be followed by a dose of PPSV-23 one year later in all adults 65 years and older. Once off vaccination with either type of pneumococcal vaccine did not confer a protective benefit in this study. This recommendation is based on guidelines in use for South Africa and other international agencies. Compliance with the guidelines vaccination schedule was found not to be the practice in our study population. For the secondary exposure, our findings reaffirm the significance of seasonal influenza vaccination for the study age cohort. We recommend that programmes to significantly enhance both pneumococcal and influenza vaccine uptake be earnestly addressed in order to address severe uptake deficiencies observed in this study. Both vaccines should be given concurrently in order to enhance compliance and to further reduce the burden of CAP for the study age cohort.
The prevalence and associations of low testosterone levels and erectile dysfunction in a male diabetic urban population
(University of Pretoria, 2014) Rheeder, Paul; kemp.tanja@gmail.com; Kemp, Tanja
Introduction: According to the literature, low serum testosterone levels are associated with diabetes mellitus. Minimal data exist for its prevalence or predictors in South Africa. Erectile dysfunction is a common condition in diabetic patients. The prevalence and predictors in our patient population is unknown. Methods: An observational, cross-sectional study was performed in 150 consecutive male diabetic patients over the age of 50 years in the Diabetic clinic of Steve Biko Academic Hospital. These patients were evaluated for diabetes control and complications, the presence of erectile dysfunction and for hypogonadism symptoms. Morning serum testosterone levels were done. Subjects with low testosterone levels were compared to those with normal levels. Results: The mean age of the patients was 62 years (standard deviation (SD) 7.87), 91.3% had type 2 diabetes, and 84.7% were on insulin. The mean duration of diabetes was 15 years (SD 8.65). The mean body mass index was 30.7 (SD 5.37), the mean waist circumference was 112.4cm (SD 16.42), the median creatinine was 96μmol/L (interquartile range (IQR) 79-133) and the median HbA1C was 7.85% (IQR 6.80-9.30). Ischaemic heart disease was previously diagnosed in 40.7% of patients. Some degree of erectile dysfunction was reported in 95.3% of the patients with 51.3% reporting serious dysfunction. The prevalence of androgen deficiency symptoms was 94.7%. Fifty percent of the men had low total testosterone levels; 40.7% had low modified calculated bioavailable testosterone levels, and in 27.3% both were low. With multivariate logistic regression the significant factors associated with low total testosterone were waist circumference and known cardiovascular disease. For a low modified calculated bioavailable testosterone level significant variables were age, diabetes duration and body mass index and for an outcome defined as both the above the significant factors were diabetes duration, body mass index, and known cardiovascular disease. With multivariate logistic regression the significant factors associated with erectile dysfunction were age, body mass index, peripheral neuropathy score, and diuretic therapy. The prevalence of symptoms of androgen deficiency was very high with 94.7% of all patients reporting a significant amount of symptoms on the Androgen Deficiency in Adult Males (ADAM) questionnaire. If only the total serum testosterone level was evaluated instead of the modified calculated bioavailable testosterone, the sensitivity was 69%, the specificity was 63%, with a poor positive predictive value of only 56%. The negative predictive value was better at 75%. Differences in quality of life scores were only seen for some erectile dysfunction subgroups but not for low testosterone levels. Conclusion: This study confirms the high prevalence of low testosterone levels and of erectile dysfunction in diabetic male patients in a tertiary setting, and argues in favour of universal screening of this population group. Multiple predictors of low testosterone levels and of erectile dysfunction were identified. The ADAM questionnaire was not useful in identifying subjects with a low testosterone level. Total testosterone testing alone performed poorly in comparison with modified calculated bioavailable testosterone and is not the recommended test of choice. Erectile dysfunction negatively affected the quality of life.
Decentralization of antiretroviral treatment in Swaziland: outcome of nurse initiated versus doctor initiated treatment.
(University of Pretoria, 2014) Rheeder, Paul; vuyomazz@yahoo.co.uk; Mazibuko, Sikhathele
Introduction: Decentralization of antiretroviral therapy (ART) services faces decreasing quality when increasing ART coverage. This study compares nurse initiated and managed patients to doctor managed patients under these circumstances, using retention in care as a crude measure of quality of care. Methods: This was an observational retrospective cohort study. A simple data abstraction tool was used to collect baseline patient data from medical records of HIV positive patients (N=871) initiating ART at Mbabane Government Hospital and four of its outreach clinics, between 1st January and 30th June 2011. Descriptive summary statistics and comparison of the two cohorts using multivariate analysis was done. Results There was no statistically significant difference in retention rates between the doctors and nurses cohorts at 69.1% and 70.9%, respectively (P was 0.56). After adjusting for sex, haemoglobin, CD4 cell count, weight and WHO stage, the odds of being retained in care were similar between the two groups, adjusted OR: 1.11(95% CI: 0.72, 1.69), with a p value of 0.64. Haemoglobin and weight were positively associated with retention in care, while male sex was negatively associated with retention in care. Discussion: The similar retention rates between the two cohorts suggest that in terms of retention in care the service provided by the nurses was comparable to that provided by doctors. This is important to ART program managers as they scale-up ART decentralization. Conclusion: Task-shifting of ART initiation from doctors to nurses is feasible as nurse initiated and managed antiretroviral therapy is comparable to doctor initiated and managed treatment.
The effect of snacking on continuously monitored glucose concentrations in analogue insulin basal bolus treatment regimens
(University of Pretoria, 2013) Rheeder, Paul; johanmoolman@live.co.za; Moolman, Lukas Johannes
No abstract available.
The cost-effectiveness of introducing Manual Vacuum Aspiration compared to Dilatation and Curettage for incomplete first trimester abortions at a tertiary hospital in Manzini, Swaziland
(University of Pretoria, 2013) Moodley, Saiendhra Vasudevan; Miot, Jacqui; cmaonei@yahoo.com; Maonei, Costa
Background: Despite proven efficacy, Manual Vacuum Aspiration (MVA) use for incomplete abortions is low in the Swaziland setting, including Raleigh Fitkin Memorial (RFM) Hospital. Uncertainty in the costs implications of introducing MVA to replace Dilatation and Curettage (D&C) is the major hindrance to change. This study aimed to evaluate the cost-effectiveness of introducing MVA as an evacuation method for first trimester incomplete miscarriages as well as assess the implications of the introduction of MVA to the entire post-abortion care budget at RFM Hospital. Methods: The methods comprised cost-effectiveness and budget impact analyses from a healthcare perspective based on a theoretical cohort. Clinical outcomes data for procedures were obtained from relevant literature. Costs were collated from prospective suppliers and then compared for the two treatment modalities. Future numbers of annual evacuations were extrapolated from previous annual figures. First trimester miscarriages were in turn extrapolated from proportions found in previous studies. Total budgets were calculated under the current scenario, as well as if MVA had to be introduced. Results: With initial capital costs of ZAR11 093.00, introduction of MVA for first trimester incomplete abortions will cut post-abortion care costs by 34.7%. MVA would cost ZAR819.86 per procedure while D&C costs ZAR1 255.40 per procedure. An estimated 26 MVA procedures done instead of D&C will compensate for the initial capital investment. Introduction of MVA into the post-abortion care programme will save the hospital about ZAR516 115.30 annually, with at least similar clinical outcomes compared to D&C. Conclusions: MVA should be considered as the first option in first trimester post abortion care.
Outcomes in malnourished children at a tertiary hospital in Swaziland : post implementation of the WHO treatment guidelines
(University of Pretoria, 2013) Hyera, Francis Leonard Mpotte; drobenyera@yahoo.com; Benyera, Oscar
Background. Swaziland adopted the World Health Organization’s (WHO) guidelines for the inpatient treatment of severely malnourished children in 2007 to reduce case -fatality rates for childhood malnutrition. However, no follow-up studies have been conducted to determine the reduction in the case -fatality rate post-implementation of the guidelines. Objectives. To determine the case -fatality rate for childhood malnutrition post-implementation of the WHO treatment guidelines and determine the level of adherence to the guidelines at Mbabane Government Hospital. Methods. A retrospective observational study was undertaken. All children under 5 years admitted for inpatient treatment of malnutrition between January 2010 and December 2011 had their demographic-, anthropometric- and clinical characteristics recorded and analysed, as well as the outcome of admission. Results. Of the 227 children admitted during the study period, 179 (64.6%) were severely malnourished and 98 (35.4%) had moderate malnutrition. One-hundred-and-eleven children died during admission, an overall case -fatality rate of 40.1%. Mortality was significantly higher among severely malnourished children compared to those with moderate malnutrition, (46.9% vs 27.6%, OR 3.0 (95% CI 1.7 to 5.3)). Comorbid pneumonia and gastroenteritis were significant predictors of mortality – , OR 2.0 (95% CI 1.2 to 3.4) and 1.9 (95% CI 1.1 to 3.2) respectively. Conclusion. Case -fatality rates for childhood malnutrition remain high, despite adoption of the WHO treatment guidelines. A need exists for improved adherence to the WHO guidelines and periodic clinical audits to reduce deaths from childhood malnutrition to meet the WHO mortality target of less than 5% and improve child survival.
Drivers of direct cost of inpatient care for HIV-infected adults at Amajuba Memorial Hospital, Mpumalanga
(University of Pretoria, 2013) Rheeder, Paul; Miot, Jacqui; dr.sbu@medics.co.za; Nhlapo, Sibusiso G
Introduction: Sub-Saharan Africa remains the region worst affected by the HIV/AIDS pandemic in the world. South Africa (SA) is the country with the highest population of people living with HIV/AIDS in the world and Mpumalanga province is the province with the second highest prevalence of HIV/AIDS in SA. The district of Gert Sibande has the highest prevalence in the province of Mpumalanga (38.9%) in 2006. Since many patients living with HIV/AIDS usually present to district hospitals as the first point of contact it is important to understand the implications of HIV/AIDS in a resource limited health system. Study setting: The setting for this study was Amajuba Memorial Hospital (AMH) a district hospital in the Gert Sibande district of the Mpumalanga province. Objective: To analyse direct costs of providing inpatient care to adult patients with HIV/AIDS-related illnesses at AMH from the perspective of the provider (hospital) Study methods: The population of study comprised adult patients with HIV/AIDS-related illnesses admitted to the medical wards during the period of October 2009 and March 2010 at AMH. A detailed retrospective record review of patients admitted to the adult wards at AMH with HIV/AIDS-related illnesses over a 6-month period was conducted. After the record review the costs were estimated using standard costs and utilisation. Demographic and clinical patient profiles were determined then descriptive statistics were calculated with total costs as an outcome variable. Subsequently univariate and multivariate regression analysis were performed. Results: The demographic and clinical profiles revealed that most patients admitted with HIV/AIDS-related illnesses were: between the ages of 39 & 49 years (35.3%), male (54.9%), urban residents (82.0%), unemployed (87.2%), single (80.5%), were not on HAART (70.7%), had CD4 counts between 0 & 50 x 106 /L (38.3%), had pulmonary tuberculosis (PTB) (38.4%), were admitted for the first time (60.9%) and of the total admitted to hospital 79.0% survived the index admission during the study period. Descriptive statistics of the continuous data variables were determined. Minimums, maximums, inter-quartile ratios, means and modes were determined and tabulated. 5 Consultation costs followed by investigation costs were the two major contributors to total admission costs (77.7% of the median total admission cost). Univariate analysis revealed these significant associations with total admission costs: admission diagnosis, discharge diagnosis, first admission, outcome, pre-admission consults and preceding admissions. In multivariate regression, admission diagnosis and pre-admission consults were analysed. Significant associations were found between the following categories: retroviral disease versus other diseases (p=0.001), retroviral disease versus anaemia (p=0.035), no pre-admission consults versus 1 pre-admission consult (p=0.007), no pre-admission consult versus 4 pre-admission consults (p=0.039) and no pre-admission consult versus 5 or more pre-admission consults (p=0.006). Conclusion: In our study we successfully determined demographic and clinical profiles of patients admitted with HIV-related illnesses at AMH. Emerging from the results of our study were patterns of burden of HIV disease, health seeking behaviour and risky sexual behaviour that all had implications for admission costs in the hospital. Major cost drivers were consultation and investigation costs, which were increased significantly by disease categories; other diseases, anaemia and PTB. Pre-admission consults emerged as a cost reducing parameter in our study.
Clinical outcomes and costs : a comparison between spinal anaesthesia and intra-venous general anaesthesia for emergency caesarean sections at a regional hospital in Swaziland
(University of Pretoria, 2013) Rheeder, Paul; Miot, Jacqui; docmajirija@yahoo.co.uk; Majirija, Edgar T
Please read the abstract in the dissertation.
Record review of the management of patients admitted for diabetic foot complications
(University of Pretoria, 2008-08-08) drrukhsana@hotmail.com; Khan, Rukhsana; Prof P Rheeder
The human burden of diabetes is a consequence of devastating chronic complications. Common complications of diabetes are micro vascular disease (nephropathy, retinopathy and neuropathy) and increased risk of macro vascular disease (stroke, heart attack and peripheral vascular disease). With the onset of neuropathy, many diabetic people are at risk of developing diabetic foot. Foot complications, especially foot ulcers, constitute a major public health problem for diabetes patients in sub-Saharan Africa and are an important cause of prolonged hospital admission and death in patients from this part of the continent Aim The descriptive study aims to determine clinical features, foot-related and cardiovascular risk factors, management, and clinical outcomes of patients admitted with diabetic foot in general surgery wards of the Pretoria Academic Hospital. Methods and Materials A retrospective audit of the surgical ward register and patient files was conducted for a period of two years – 2005 to 2006. All those patients who were admitted for the first time with diabetic foot complication were included in the analysis. Results: Patients admitted with diabetic foot complications were 2.52 % and 4.58% out of the total admissions in female and in male surgical wards respectively. A total of 81 records were identified, reviewed and analysed. Results of the study showed that 54.3% (n=44) were females and the mean age of the sample was 61.44 (+ 12.9) years. Of the total number of patients 18.5 % (n 15) were smokers, 29.6% (n=24) had never smoked, and 37% (n=30) were ex-smokers. Peripheral pulses were examined in 85% and in 18% of cases; both pulses were absent in the affected foot. Assessment of neurological status using Semmes Weinstein 5.07 monofilament was not done or other non-specific methods were used. Ulcers were assessed in 44% of cases but the documentation of size of site and appearance was poor. No classification system or grading of ulcers was used. Regarding cardiovascular risk; 67% had HT and were taking treatment. Lipid values were measured in less than 10% of subjects. Renal function was measured in 94%. Of all admissions 48% had below knee and 18.5 % above knee amputations. Approximately 33% of patients were readmitted, of which 23% of admissions were for problems in the same foot. On discharge 43% were prescribed ACE inhibitors, 33% aspirin and only 12% statins. Very few ( n=03) patients reached the Diabetic Clinic of Pretoria Academic Hospital for follow up in the three months following discharge and none in reached the Kalafong Diabetic Clinic. Conclusions This study found that there was no standardised protocol for ulcer grading, detection of neuropathy or evaluation of cardiovascular risk. Long-term care of these patients could possibly be improved by involving other disciplines during the admission of patients with diabetic foot.
A retrospective cohort analysis of antiretroviral treatment modifications at the referral HIV clinic in Mbabane, Swaziland
(University of Pretoria, 2010) Louwagie, Goedele M.C.; Zuma, Khangelani; stakuva@wltshealth.co.za; Takuva, Simbarashe G.
Background: Optimizing initial antiretroviral therapy (ART) regimens is of paramount importance in improving the durability of treatment efficacy and patient prognosis. We evaluated the reasons for and risk factors relating to ART modifications in an outpatient cohort in Mbabane, Swaziland. Methods: Retrospective cohort analysis of data for 782 patients who started first-line ART between 1 March 2006 and 31 March 2008. Multivariate piecewise Cox regression models were used to identify potential predictors of treatment modification. Results: Over a median follow-up period of 21 months, 17.5% of patients modified their regimen. Drug toxicity was the commonest reason (77 %) while drug contra-indications, namely tuberculosis (13.1%) and pregnancy (6.6%) accounted for 20% of the modifications. In the adjusted multivariate Cox piecewise regression model; after 11 months on ART, baseline CD4 cell count < 200cells/mm3 (HR = 4.42; 95% CI: 1.62 – 12.1), having Stavudine (d4T) in the initial regimen (HR = 2.64; 95% CI: 1.56 – 4.46) and baseline weight > 60kg (HR = 2.40; 95% CI: 1.43 – 4.04) significantly increased the hazards for modification. Conclusions: Initiating HAART at higher CD4 counts, avoiding drugs with poor safety profiles, such as Stavudine (d4T), and identifying individuals who may require therapy for tuberculosis or who may become pregnant could reduce modification rates.
The association between meteorological parameters and the prescription patterns for asthma and allergic rhinitis, as observed in Pretoria during a one-year period
(University of Pretoria, 2006-11-30) Rheeder, Paul; upetd@up.ac.za; Retief, Johannes Hendrik
Please read the abstract in the 00front part of this document
The effect of falciparum malaria prevalence on the effectiveness of intermittent preventive treatment with Sulfadoxine-Pyrimethamine during pregnancy in reducing low birth weight in southern Mozambique
(University of Pretoria, 2013-01-07) Rheeder, Paul; Barnes, K.I.; yascassam@gmail.com; Cassam, Yasmin
Malaria infection is a major cause of morbidity and mortality in tropical countries, and particularly in Mozambique. Recently substantial resources have been used to reduce the burden of malaria in Mozambique. These include the distribution of insecticide treated bed-nets, indoor residual insecticide spraying, access to artemisinin-based combination treatment (ACT), and intermittent preventive treatment of pregnant women with sulfadoxine-pyrimetamine (SP-IPTp). The most important benefit of SP-IPTp in malaria endemic areas has been the increase in birth weight, thus increasing the probability of child survival. The SP-IPTp policy was based on evidence of its effectiveness in areas of high intensity malaria transmission. The effect of SP-IPTp has been less evident in the presence of high coverage with insecticide treated bed-nets. It is not know whether reducing the risk of malaria through effective vector control using indoor residual insecticide spraying and large-scale deployment of ACTs has a similar effect in reducing the impact of SP-IPTp on birth weight. At the same time, increasing resistance of SP could be compromising the effect of SP-IPTp on birth weight, as could co-infection with HIV. The aim of this study was to determine if the effect of SP-IPTp on reduction in risk of low birth weight is modified by Plasmodium falciparum malaria prevalence. This retrospective antenatal record review, analyzed 20867 antenatal records from 2005 to 2007 from public health facilities in Maputo and Gaza provinces, southern Mozambique. One or two doses of SP-IPTp does not have any effect on reducing the risk of low birth weight, while women who had at least three doses of SP-IPTp had a 15% lower risk of their babies being born with low birth weigh compared with fewer doses, (OR=0.85; 95% CI 0.73 – 1.00; p=0.053). The risk of babies being born with low birth weight was reduced by 28% when both malaria prevalence and dhfr / dhps mutation prevalence are low, (OR=0.72; 95% CI 0.51 – 1.00), but this effect was no longer significant with higher malaria prevalence and or mutation prevalence. SP-IPTp has an effect on reducing low birth weight with three or more doses, and in areas where malaria prevalence and mutation prevalence are low. Copyright
Morbidity and mortality patterns among the under 5 year old children admitted to district hospitals in the Eastern Cape, 2000 - 2004
(University of Pretoria, 2010-10-06) Matjila, Maila J.; upetd@up.ac.za; Dlamini, Thomas
Introduction.: The evaluation and improvement of the quality of health care services begins with the knowledge about the trends and causes of diseases. Purpose: To describe the morbidity and mortality patterns for the under-5 year old children who were admitted in 11 district hospitals in Eastern Cape Province from 2000 to 2004. Methods: Descriptive study where a multi-stage sampling technique was used to select 11 district hospitals. There were 25,122 causes of paediatric ward admissions (2000 to 2004) among under-5 children from ward register were reviewed and ICD-10 coded. Findings: Pre-transitional causes were the leading causes of morbidity (68.4%) and mortality (74.2%) especially diarrhoeal lower respiratory tract infections and protein-energy malnutrition. There was particularly among male high infant morbidity and mortality rates observed from 2000 to 2004. Non-communicable diseases (8% morbidity and 4.2% mortality) and injuries (10% morbidity and 4.4% mortality) appeared to be of less public health concern among the under-5 children. Majority of under-5 mortality (43.4%) occurred within 24 hours of admissions (23.7% died on arrival). Influential variables for morbidity and mortality were region (Eastern), age (infants), year admitted and broad classification of the diseases (group I causes). There was a constant increase in morbidity and mortality which was observed during studied period. Conclusion: Pre-transitional causes (especially diarrhoeal, lower respiratory tract infections and protein energy malnutrition) were of public health concern among the under-5 children and their magnitude has increased over the years studied. Copyright
Screening for childhood anaemia using copper sulphate densitometry
(University of Pretoria, 2005-09-22) Rheeder, Paul; upetd@up.ac.za; Funk, Maryke
The objective of this study was to evaluate copper sulphate densitometry as a screening method for anaemia in children. The accuracy of copper sulphate densitometry was also compared to clinical assessment for the presence of pallor and haemoglobin measurement with a BMS-haemoglobinometer. Different observers performed these three screening tests independently. For the purposes of this study, anaemia was defined as a laboratory haemoglobin (Hb) concentration below 10 g/dl. A cross-sectional screening study was undertaken, where the results of the different screening tests were compared to laboratory haemoglobin determination (gold standard). The study sample consisted of one hundred consecutive children, aged between 6 months and 6 years, whose parents had given informed written consent for participation. The study was conducted in the Paediatric Outpatient Department of Pretoria Academic Hospital (73 children) and a local creche (27 children). In this study sample, the prevalence of anaemia (Hb < 10 g/dl) was 17% (95% Confidence Interval (95%CI) 10.2; 25.8). Clinical assessment by students for the presence of pallor had a sensitivity of 41.2% (95%CI 19.4; 66.5), specificity of 81.9% (95%CI 71.6; 89.2), positive predictive value of 31.8% (95% CI14.7; 54.9) and negative predictive value of 87.2%(95%CI 77.2; 93.3). The likelihood ratio for detection of anaemia by clinical assessment was 2.3. Copper sulphate densitometry had a sensitivity of 88.2% (95%CI 62.3; 97.9), specificity of 89.2% (95%CI 79.9; 94.6), positive predictive value of 62.5% (95% CI 40.8; 80.5) and negative predictive value of 97.4% (95%CI 90.0; 99.5) to screen for anaemia. The Likelihood Ratio of a positive copper sulphate-screening test was 8.17. On average, haemoglobin concentration was underestimated by 0.29 g/dl with the BMS-haemoglobinometer, with the 95% limits of agreement ranging from underestimation by 1.3 g/dl to over-estimation by 1.9 g/dl. Logistic regression analysis revealed that both the copper sulphate test and measurements with the BMS-haemoglobinometer predicted anaemia accurately. The area under the Receiver Operating Characteristic (ROC) curve for the haemoglobinometer was 0.94 (95%CI 0.87; 1), while the area under the curve for copper sulphate densitometry was 0.89 (95% CI 0.73; 1). Used together, the area under the ROC curve was 0.95 (95% CI 0.89; 1). In resource-poor settings, copper sulphate densitometry could be an accurate, inexpensive and simple screening method for anaemia in children.
The efficacy of an intervention program aimed at diabetes care physicians regarding quality of diabetes care at a tertiary care hospital
(University of Pretoria, 2003) Rheeder, Paul; upetd@up.ac.za; Van Zyl, Danie G.
Please read the abstract in the section, 00front, of this document
An educational intervention to improve the quality of care of diabetic patients
(University of Pretoria, 2003) Rheeder, Paul; upetd@up.ac.za; Oosthuizen, Helena
Please read the abstract in the section, 00front, of this document
Depression scores in a cohort of HIV positive women followed from diagnosis in pregnancy to eighteen months postpartum
(University of Pretoria, 2010-08-03) Rheeder, Paul; Kershaw, Trace S.; j.makin@up.ac.za; Makin, J.D. (Jennifer Dianne)
Background Depression has been found in the literature to be a major problem in people living with HIV/AIDS. Not only does this impact on their daily functioning but has been shown to have negative HIV related outcomes, and result in poorer adherence to antiretroviral medication. The population under study was pregnant at the time of diagnosis. It would seem likely that their risk for depression would be greater than even a general HIV infected population, because of the pregnancy and the fact that they might have concerns around the health and future of the unborn infant. There are a limited number of studies looking at levels of depression over time and possible determinants of this depression even in a general HIV infected population. It was thus felt necessary to establish levels of depression and to establish if there were any factors associated with changes over time in this pregnant population. Method Two hundred and ninety three women were recruited at antenatal clinics in Tshwane from June 2003 and December 2004. They were interviewed at approximately 28 weeks gestational age and were followed for 18 months after the birth. Data included socio demographic variables, a “self efficacy score”, past history of violence, disclosure, CD4 count and knowledge score. Psychological variables included measures of stigma, social support, self esteem and coping. Depression was measured using a modified CES-D (Center for Epidemiological Studies Depression Score) Repeated measures mixed linear analysis was used to assess if there were changes in depression scores over time and if there were factors associated with these changes. Results Two hundred and twenty four women were included in the mixed linear analysis. The mean age of the women was 26.5 years (standard deviation -5.1). Seventy six percent (152) were single with a partner. Seventy six percent (171) had some form of secondary education and 14% (32) had some form of tertiary education. Sixty percent (135) lived in a brick house and 35% (79) had running water in the house. Twenty nine percent (64) had a per capita income below the poverty line. The prevalence of borderline depression (CES-D scores above 12) for this group of women at baseline was 45%. There were significant changes in depression scores over time. This was not a linear relationship (significant quadratic time to interview term p=0.008). This was evidenced by the fall off in scores at 3-9 months followed by a subsequent rise. The factors associated with higher depression scores overall were lower active coping (p=0.004), higher avoidant coping (p=0.003), higher internalised stigma (p=0.001), higher housing scores (0.026), lower self–esteem (0.002), a history of violence (p<0.0001) and having no partner (p=0.005). No factors were associated with changes over time. Conclusion There are significant changes in depression scores over time in this cohort of women Depression scores while falling after the birth of the child as in other cohorts, start to rise again. Although there are no specific factors associated with these changes, overall women who have a history of violence, who have no partner, who live in better housing circumstances, who have poor self esteem, who have high levels of internalized stigma and make use of negative coping strategies are more likely to be depressed. Women who make use of active coping strategies are less likely to be depressed. There are a large number of women at baseline who have scores considered to be diagnostic of borderline depression and because of the potential negative consequences to the woman and child, an intervention aimed at addressing the above issues should be devised. This should start in the antenatal period and carry on beyond this time. Copyright
Comparison of vascular and neurological parameters between diabetic subjects without diabetic foot ulceration or amputation and those with either foot ulceration or a lower extremity amputation : a pilot study
(University of Pretoria, 2007-07-24) Rheeder, Paul; mcduim@med.up.ac.za; Duim-Beytell, Martha Catharina
Background: It is likely that lower limb ulceration, lower limb amputation, or their absence in diabetic subjects, indicate varying degrees of long-term diabetes and its complications, and that measures of atherosclerosis and neuropathy would reflect these differences. Objectives: To determine feasibility and, based on our results, make sample size estimates for future study: By comparing peripheral and central vasculature between diabetic subjects with lower extremity ulcers, diabetic subjects with lower extremity amputation and a group of diabetics without these complications — through evaluating toe blood pressure (TBP), toe-brachial index (TBI) and pulse wave velocity (PWV); also, by comparing peripheral and autonomic nervous system integrity between these groups — through sensory, nerve conduction, needle-examination and autonomic function assessment. Study design: A cross-sectional, descriptive and comparative pilot study. Setting: Pretoria Academic Hospital. Participants: Three groups of ten patients consecutively selected from diabetes and diabetic foot clinics — ten with chronic lower extremity ulcers, ten with healed lower extremity amputations and ten diabetic controls. Methods: Assessment of peripheral and autonomic neuropathy included evaluation of 5.07/10-g monofilament sensation, vibration perception (using a 128Hz tuning fork), nerve conduction and electromyography, cutaneous autonomic response and heart rate variability (expressed as an Expiration: Inspiration (E:I)-ratio). For evaluation of vascular status, we obtained the photo-plethysmographically-derived TBI and assessed carotid-femoral (CF) and carotid-radial (CR) PWV. Sample sizes for future studies were calculated through a nomogram for three-group comparisons, ANOVA, simulation and log-transformation of non-parametric data. Results: Absence of vibration perception in at least one leg, with significant p-values of 0.000 at toe-, and 0.027 at medial malleolus- level, occurred more frequently in the amputation, than in the control group. For the total bilateral monofilament count a statistically significant difference between groups was demonstrated (p-value 0.043). Peripheral neuropathy based on abnormality of at least one conduction attribute in at least two distinct nerves, the E:I-ratio, assessment of cutaneous autonomic responses and TBI, by worsening across groups, seemed to display a correlation with severity of lower limb complications, but without statistically significant results. For CF- and CR PWV, the lowest values were observed in the amputation group. Sample size calculations based on our TBP, TBI, vibration and monofilament results, lead to a proposed equal group size of between 34 and 103 for future three-group comparisons using these outcomes measures. Should PWV be included, the group size would have to be between 160 and 222. Conclusions: This study confirmed the usefulness of monofilament sensation and vibration perception assessment in identifying diabetic patients with differing degrees of lower extremity risk. Also, due to the large differences between groups, it demonstrated the effectiveness of these measures to display differences between groups, even in the event of very small sample sizes. The tendencies to worsen across the three groups, of the E:I -ratio, peripheral neuropathy based on nerve conduction, and the TBI, will have to be re-examined in a study with larger sample size. In order to demonstrate statistically significant CF- and CR PWV results, a larger sample size may also be required.
Immunogenicity and toxicity of yellow fever vaccines : a systematic review
(University of Pretoria, 2010) Rheeder, Paul; nmakhunga21@mweb.co.za; Makhunga-Ramfolo, Nondumiso Siphosakhe
BACKGROUND Yellow fever (YF) is a non-contagious, mosquito borne haemorrhagic fever caused by a single-strand RNA flaviviruses. YF is endemic in the tropics primarily in South America and Africa although the vectors are present in Asia, Europe, Pacific and Middle East. Human beings serve as viraemic hosts for mosquito infection. YF carries a high burden of disease, particularly in developing countries with up to 200 000 cases reported annually and a case fatality rate of 20-50%.The pathogenesis is poorly understood and little research has been conducted .There is no known cure or specific treatment for YF and prevention remains the mainstay the public health approach in terms of effectiveness and cost. The World Health Organisation (WHO) conventions have made vaccination mandatory for travel to endemic countries to prevent outbreaks and transmission to susceptible individuals. YF vaccine is one of the oldest vaccines known and in use and is derived from an attenuated virus strain 17D originally produced in the 1930s. The vaccine has historically been considered effective and safe. However, severe life-threatening side effects to the vaccine have been reported in the past 20 years. Acute vaccinerelated viscerotropic (AVD) and neurotropic (AND) side effects have been reported globally particularly in the elderly. The adverse reactions typically present as YF- like illness resulting in multi-organ failure with death as a possible outcome. OBJECTIVES To estimate the immunogenicity and toxicity of 17D and 17DD YF vaccines by summarizing the available data from randomised controlled trials. STUDY DESIGN A summary of randomized controlled trials (RCT) of YF vaccine immunogenicity and safety and tolerability was obtained using standard meta-analysis methodologies. METHODS A comprehensive literature search was conducted in order to identify trial that met with predetermined inclusion and exclusion criteria. Features of each study were noted taking into account the type of vaccine used, the duration of follow up, assignment to intervention, blinding and randomization methods. Three studies were eventually pooled and effect size estimates reported in each study were noted and analysed using meta-analysis software, MIX. Reports on the side effects post vaccination were summarized and analysed. RESULTS The difference in outcomes between the standard 17DD YF vaccines intervention, traded as Arilvax ® and the 17D YF vaccines traded as YF-Vax ® and Stamaril ® was negligible in terms of effect size. Effect sizes that considered the means between the treatment and control groups demonstrated a difference that favoured the control group viz. Arilvax ®. The pooled results also showed significant publication bias most likely attributable to the small number of studies considered. The pooled and annotated forest plot supported the available literature in confirming the effectiveness of YF vaccines in conferring immunity. A summary of tolerability events CONCLUSIONS This study has confirmed the effectiveness of YF vaccines in terms of immunogenicity and also demonstrated that YF vaccines are well tolerated and safe The small number of study units considered in this study presented challenges for analysis and for interpretation but highlighted the need for more research to be conducted in this area. The results are in keeping with the existing body of evidence supporting the robustness of the immunological response to YF vaccination. The safety and tolerability of the vaccine established in this study was also consistent with known literature. There are important implications for further research and implementation that became evident such as the need for further studies to be conducted in African populations where the burden of disease is highest.
Identification of predictors of glucose control in a cohort of adult patients with diabetes mellitus at Kalafong Hospital
(University of Pretoria, 2011-07-14) Rheeder, Paul; tessy.dr@gmail.com; Mutembe, Tessy Karimba
Background and objectives of the study: Although it is known that good glycaemic control improves microvascular outcomes in diabetic patients, no local study has yet been undertaken to investigate the potential factors that influence poor or good blood glucose control. This research focused on the evaluation of blood glucose control as assessed by glycosylated haemoglobin (HbA1c) levels in diabetic patients. In addition, certain determinants which contributed toward poor control at Kalafong Hospital were studied in a cohort of adults with diabetes mellitus for the year 2008. The aim of studying these determinants was to identify patients with a high risk of disease morbidity and barriers that prevent these patients from meeting their goals of improved health outcomes. The specific objectives were to estimate HbA1c control of patients seen at the diabetic clinic at Kalafong Hospital Pretoria in 2008 and to assess any existing association between patient demographic characteristics and diabetes characteristics with HbA1c. Methods: The study was a retrospective cohort study. All diabetic patients aged 18 years and above, who had been registered in the 2008 dataset and who had come for at least one visit to the diabetic clinic and had at least one HbA1C measurement, were included in the study. Patients who did not meet the above criteria were excluded from the study. A total of 942 patients seen in 2008 were selected, 801 patients met these inclusion criteria. The outcome variable HbA1c was obtained by computing the mean of the two HbA1c values collected for each participant for the year 2008, and used as a continuous dependent variable in multivariate linear regression. For descriptive purposes, HbA1c values were categorised into good control (<7%), poor control (> or = 7&< or =10%) and very poor control (>10%). Data analysis was performed using Stata version 10. Statistical significance was established at a threshold of 95% (p < 0.05). Results: More than half of participants in the study were females (60.8%/39.2%). The mean age of participants in the study was 56 years (sd 14.1). With regard to race, the proportion of blacks was more than three quarters of the sample (93.1%/2.4%/2.4%). Our results showed that HbA1c level decreased with increasing age, (p = 0.016). These results also showed that for every 1 mmol/l increase in total cholesterol, there was a 0.178% increase in HbA1c, (p = 0.019; 95% confidence interval (CI): 0.030 - 0.327), suggesting that higher cholesterol was associated with poorer HbA1c control. In addition, for every 1 mmol/l increase in capillary glucose, the HbA1c increased by 0.276%, (p = 0.000; CI: 0.230 - 0.322) while for every one unit increase in BMI, the HbA1c reduced by 0.032%, (p = 0.017; CI: -0.057 to -0.006). Conclusion: These results suggest that patients with higher total cholesterol and patients with higher capillary glucose level are more likely to exhibit poorer HbA1c control, whereas, older patients and patients with a higher BMI are more likely to have better HbA1c control.

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