The present series of investigations examined the diagnostic accuracy of the Cognitive Examination (CAMCOG) from the Cambridge Mental Disorders of the Elderly Examination (CAMDEX) in the differential diagnosis of various dementing conditions. Specifically, this study examined: (a) the degree to which the CAMCOG would differentiate normal individuals from patients with Alzheimer's Disease (AD) and from those suffering from non-AD dementing conditions, (b) the extent to which the CAMCOG would distinguish between patients suffering from organic dementing conditions, those having functional psychiatric disorders, and normal persons, and (c) whether the CAMCOG would offer an improvement in diagnostic accuracy over a widely used screening instrument (i.e., the Mini-Mental Status Examination, MMSE) when attempting to differentially diagnose dementing patients and normal cohorts.A review of the literature was presented with an emphasis on the difficulties in establishing differential diagnosis, inaccuracies in diagnosis, the importance of improved diagnostic accuracy, and the use of neuropsychological measures in the assessment and diagnosis of patients suffering from dementing illnesses. Further, research relevant to ancillary diagnostic techniques, the various neuropsychologicalapproaches used in evaluating and diagnosing mental disorders in the elderly, and studies investigating the utility of specific cognitive/neuropsychological measures in the differential diagnosis of dementing diseases was presented.The results of these investigations revealed that the CAMCOG provides excellent diagnostic sensitivity and specificity when differentiating normal persons from clinically diagnosed AD patients and when distinguishing between individuals with an organic-dementing condition and normal adults. The CAMCOG was found to be less effective in differentiating AD and non-AD dementia patients and in distinguishing between patients suffering from organic dementia versus specified psychiatric disorders. Finally, the CAMCOG demonstrated a slight improvement in diagnostic accuracy over the Mini-Mental Status Examination. These results were discussed in terms of their support for the utility of the CAMCOG as an excellent screening measure when used to differentiate patients suffering from various dementia-producing disease states and normal persons. / Department of Educational Psychology

Cardiovascular disease is a serious life-threatening disease. It can occur suddenly and progresses rapidly. Finding the right disease features in the early stage is important to decrease the number of deaths and to make sure that the patient can fully recover. Though there are several methods of examination, describing heart activities in signal form is the most cost-effective way. In this case, ECG is the best choice because it can record heart activity in signal form and it is safer, faster and more convenient than other methods of examination. However, there are still problems involved in the ECG. For example, not all the ECG features are clear and easily understood. In addition, the frequency features are not present in the traditional ECG. To solve these problems, the project uses the optimized CWT algorithm to transform data from the time domain into the time-frequency domain. The result is evaluated by three data mining algorithms with different mechanisms. The evaluation proves that the features in the ECG are successfully extracted and important diagnostic information in the ECG is preserved. A user interface is designed increasing efficiency, which facilitates the implementation.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Plant virus identification and characterization can be achived by several methods based in the biological, morphological, cytological, serological and molecular virus properties. The molecular properties have been used with frequency for vÃrus identification and characterization and the reverse transcription polymerase chain reaction (RT-PCR) has constituted an efficient and precise method for researches with RNA plant viruses. On the other hand, the enzyme-linked immunosorbent assay (ELISA) is the most used serological method for virus detection in plant tissues. A techncal innovation developed for plant virus identification represents a great technological development and support for plant virus research. A new approach involving virus particle immune precipitation to be used for RNA amplification by RT-PCR named IP-RT-PCR was sucessefuly used for amplification of RNA fragments from five virus species from the genera Comovirus, Cucumovirus, Potyvirus and Sobemovirus. Considering that the immune biological Companies have developed several DAS-ELISA kits, but neither of them produce and commercialize PTA-ELISA kits, a simple and practical PTA-ELISA kit was developed and validated for plant virus detection. The second part of the research had the objective to study, comparatively, the biological, serological and molecular properties of four plant virus isolates obtained from naturally infected Passiflora edulis (PWV-PET and PWV-GUA) and from naturally infected Vigna unguiculata (CABMV-BV and CABMV-FOR) with the objective to elucidate the identity of the causal agent of passion fruit woodiness in Brazil. In host range studies onle Canavalia ensiformes and Macroptilium lathyroides were infected by virus isolates obtained from cowpea and from passion fruit. The isolate PWV-GUA was purified from systemically infected M. lathyroides plants and the virus purified preparation (18.24 mg of virus.ml-1) was used for rabitt immunization for polyclonal antiserum production, which showed a title of 1:128,000 in PTA-ELISA. The electrophoresis analysis of the purified virus showed a unique capsidial protein with 34 kDA. Plant virus interaction studies in C. ensiformis indicated unilateral cross protection between PWV-GUA and CABMV-FOR. On the other hand, the isolate PWV-PET did not cross protect passion fruit plants against PWV-GUA. Filogenetic analysis of nucleotiode sequencies from cDNA fragments corresponding to coat protein (CP) genes amplified by IP-RT-PCR from the genomic virus isolates compared with virus sequencies from the Genbank grouped according to the host specifities. Based on the biological, serological and mainly molecular results, the virus isolates studied were classified into two biotypes: Biotype CABMC-C (Cowpea) to include isolates obtained from cowpea that do not infect passion fruit, and biotype CABMV-P (Passion fruit) to include the virus isolates responsible for the passion fruit woodiness in Brazil. / A identificaÃÃo e a caracterizaÃÃo de vÃrus de planta podem ser realizadas por vÃrios mÃtodos envolvendo propriedades morfolÃgicas, biolÃgicas, citolÃgicas, moleculares e sorolÃgicas. As tÃcnicas moleculares tÃm sido usadas com frequencia para identificaÃÃo e caracterizaÃÃo de vÃrus, e a tÃcnica de âreverse transcription polymerase chain reactionâ (RT-PCR) tem se constituÃdo em mÃtodo eficiente e preciso para pesquisas com vÃrus de planta com genoma de RNA. De outra parte, a tÃcnica de enzyme-linked immunosorbent assay (ELISA) constitui o mÃtodo sorolÃgico mais usado para detecÃÃo de vÃrus em tecidos vegetais. Uma inovaÃÃo tecnolÃgica desenvolvida nesta pesquisa para diagnose de vÃrus de planta representa grande avanÃo tecnolÃgico e suporte para pesquisa em virologia vegetal. A inovaÃÃo envolvendo a imunoprecipitaÃÃo (IP) de partÃculas de vÃrus para uso na RT-PCR denominada de IP-RT-PCR foi usada com sucesso para amplificaÃÃo de fragmentos de RNA de cinco espÃcies de vÃrus dos gÃneros Comovirus, Cucumovirus, Potyvirus e Sobemovirus. Considerando que kits de DAS-ELISA tÃm sido produzidos e comercializados por companhias de imunobiologicos, mas nenhuma companhia produz kits de PTA-ELISA, um kit simples e prÃtico de PTA-ELISA foi desenvolvido e validado para detecÃÃo de vÃrus de planta. A segunda etapa da pesquisa teve como objetivo estudar as propriedades biolÃgicas, sorolÃgicas e moleculares de isolados de vÃrus do gÃnero Potyvirus obtidos de maracujazeiro (Passiflora edulis) (PWV-PET e PWV-GUA) e isolados de Cowpea aphid-borne mosaic virus (CABMV-FOR e CABMV-BV) obtidos de feijoeiro caupi (Vigna unguiculata), visando elucidar a identidade do agente causal do endurecimento dos frutos do maracujazeiro no Brasil. Em estudos de gama de plantas hospedeiras, somente Canavalia ensiformis e Macroptilium lathyroides foram infetadas por isolados obtidos de maracujazeiro e de feijoeiro caupi. O PWV-GUA foi purificado a partir de plantas de M. lathyroides sistemicamente infetadas e a preparaÃÃo viral purificada (18,24 mg de vÃrus.ml-1) foi usada para imunizaÃÃo de coelho com a produÃÃo de antissoro policlonal com tÃtulo de 1:128.000 em PTA-ELISA. AnÃlise eletroforÃtica da preparaÃÃo viral purificada revelou uma Ãnica proteÃna capisidial com peso molecular de 34 kDa. Experimentos de interaÃÃo entre os isolados virais em C. ensiformis indicaram proteÃÃo unilateral entre PWV-GUA e CABMV-FOR. De outra parte, o isolado PWV-PET nÃo protegeu plantas de maracujazeiro contra a super infecÃÃo de PWV-GUA. AnÃlises filogenÃticas das seqÃÃncias dos fragmentos de cDNA correspondentes Ãs capas protÃicas (CP), amplificados a partir dos genomas dos isolados virais de maracujazeiro e de feijoeiro caupi por IP-RT-PCR, agruparam-se com as seqÃÃncias de isolados virais de referidas culturas depositadas no GenBank, apresentando um agrupamento em funÃÃo da especificidade de hospedeiros. Com base nos resultados dos estudos biolÃgicos, sorolÃgicos e, sobretudo moleculares, os isolados virais estudados foram classificados em dois biÃtipos: BiÃtipo CABMV-C (Cowpea) incluindo os isolados obtidos de feijoeiro caupi e biÃtipo CABMV-P (Passion fruit) para incluir os isolados responsÃveis pelo endurecimento dos frutos do maracujazeiro no Brasil.

Background. This Thesis addresses the critical issue of disease management in ricecrops, a key factor in ensuring both food security and the livelihoods of farmers. Objectives. The primary focus of this research is to tackle the often-overlooked challenge of precise disease localization within rice plants by harnessing the power of deep learning techniques. The primary goal is not only to classify diseases accurately but also to pinpoint their exact locations, a vital aspect of effective disease management. The research encompasses early disease detection, classification, andthe precise identification of disease locations, all of which are crucial components of a comprehensive disease management strategy. Methods. To establish the reliability of the proposed model, a rigorous validation process is conducted using standardized datasets of rice plant diseases. Two fundamental research questions guide this study: (1) Can deep learning effectively achieve early disease detection, accurate disease classification, and precise localizationof rice plant diseases, especially in scenarios involving multiple diseases? (2) Which deep learning architecture demonstrates the highest level of accuracy in both disease  diagnosis and localization? The performance of the model is evaluated through the application of three deep learning architectures: Masked RCNN, YOLO V8, and SegFormer. Results. These models are assessed based on their training and validation accuracy and loss, with specific metrics as follows: For Masked RCNN, the model achieves a training accuracy of 91.25% and a validation accuracy of 87.80%, with corresponding training and validation losses of 0.3215 and 0.4426. YOLO V8 demonstrates a training accuracy of 85.50% and a validation accuracy of 80.20%, with training andvalidation losses of 0.4212 and 0.5623, respectively. SegFormer shows a training accuracy of 78.75% and a validation accuracy of 75.30%, with training and validation losses of 0.5678 and 0.6741, respectively. Conclusions. This research significantly contributes to the field of agricultural disease management, offering valuable insights that have the potential to enhance crop yield, food security, and the overall well-being of farmers

The relationship between the PQ-segment slope on ST-segment depression during vigorous exercise was examined in 26 apparently healthy females between 18 and 26 years of age. Each subject performed 2 submaximal cycle ergometer exercise tolerance tests (trial A and trial B) on nonconsecutive days wherein the following variables, as delta scores, were measured; P-wave amplitude (microvolts), PQ-segment slope (uV!sec), and J-point at 0 and 60 msec (uV). Each variable was measured by both visual and computer averaging. The degree of reproducibility within and between trials differed for the visual and computer averaged measures. Generally higher reproducibility was found with computer averaging particularly within trial B (r =0.63-0.89, p<O.OI). Trial b served as a basis for assessment of PQ-segment slope effect on ST segment response. Computer analysis of frequency distribution for responses revealed a greater frequency of downsloping PQ-segment with clinically significant ST-segment depression (>50 uV) at both 0 and 60 msec after the J-point in lead II. However, there was a greater percentage (91%) of flat PQ-segment slopes with clinically significant ST-segment depression at J-point 0 msec in lead V5. These findings suggest possible influence of lead selection on the measurements of the PQ-segment slope and ST-segment. Implication of clinical application would be to use lead VS for diagnosing CHD and by measuring ST-segment depression at J-point 60 msec. However when screening exercise ECG tests in apparently healthy women use J-point at 0 msec. / Master of Science

Magnetic Resonance Imaging (MR Imaging, or MRI) offers superior soft-tissue contrast compared to other medical imaging modalities. However, access to MRI across developing countries ranges from prohibitive to scarcely available. The lack of educational facilities and the excessive costs involved in imparting technical training have resulted in a lack of skilled human resources required to operate MRI systems in developing countries. While diagnostic medical imaging improves the utilization of facility-based rural health services and impacts management decisions, MRI requires technical expertise to set up the patient, acquire, visualize, and interpret data. The availability of such local expertise in underserved geographies is challenging. Inefficient workflows and usage of MRI result in challenges related to financial and temporal access in countries with higher scanner densities than the global average of 5.3 per million people. MRI is routinely employed for neuroimaging and, in particular, for dementia screening. Dementia affected 50 million people worldwide in 2018, with an estimated economic impact of US $1 trillion a year, and Alzheimer’s Disease (AD) accounts for up to 60–80% of dementia cases. However, AD-imaging using MRI is time-consuming, and protocol optimization to accelerate MR Imaging requires local expertise since each pulse sequence involves multiple configurable parameters that need optimization for acquisition time, image contrast, and image quality. The lack of this expertise contributes to the highly inefficient utilization of MRI services, diminishing their clinical value. Augmenting human capabilities can tackle these challenges and standardize the practice. Autonomous and time-efficient acquisition, reconstruction, and visualization schemes to maximize MRI hardware usage and solutions that reduce reliance on human operation of MRI systems could alleviate some of the challenges associated with the requirement/absence of skilled human resources. We first present a preliminary demonstration of AMRI that simplifies the end-to-end MRI workflow of registering the subject, setting up and invoking an imaging session, acquiring and reconstructing the data, and visualizing the images. Our initial implementation of AMRI separates the required intelligence and user interaction from the acquisition hardware. AMRI performs intelligent protocolling and intelligent slice planning. Intelligent protocolling optimizes contrast value while satisfying signal-to-noise ratio and acquisition time constraints. We acquired data from four healthy volunteers across three experiments that differed in acquisition time constraints. AMRI achieved comparable image quality across all experiments despite optimizing for acquisition duration, therefore indirectly optimizing for MR Value – a metric to quantify the value of MRI. We believe we have demonstrated the first Autonomous MRI of the brain. We also present preliminary results from a deep learning (DL) tool for generating first-read text-based radiological reports directly from input brain images. It can potentially alleviate the burden on radiologists who experience the seventh-highest levels of burnout among all physicians, according to a 2015 survey. Next, we accelerate the routine brain imaging protocol employed at the Columbia University Irving Medical Center and leverage DL methods to boost image quality via image-denoising. Since MR physics dictates that the volume of the object being imaged influences the amount of signal received, we also demonstrate subject-specific image-denoising. The accelerated protocol resulted in a factor of 1.94 gain in imaging throughput, translating to a 72.51% increase in MR Value. We also demonstrate that this accelerated protocol can potentially be employed for AD imaging. Finally, we present ArtifactID – a DL tool to identify Gibbs ringing in low-field (0.36 T) and high-field (1.5 T and 3.0 T) brain MRI. We train separate binary classification models for low-field and high-field data, and visual explanations are generated via the Grad-CAM explainable AI method to help develop trust in the models’ predictions. We also demonstrate detecting motion using an accelerometer in a low-field MRI scanner since low-field MRI is prone to artifacts. In conclusion, our novel contributions in this work include: i) a software framework to demonstrate an initial implementation of autonomous brain imaging; ii) an end-to-end framework that leverages intelligent protocolling and DL-based image-denoising that can potentially be employed for accelerated AD imaging; and iii) a DL-based tool for automated identification of Gibbs ringing artifacts that may interfere with diagnosis at the time of radiological reading. We envision AMRI augmenting human expertise to alleviate the challenges associated with the scarcity of skilled human resources and contributing to globally accessible MRI.

In healthcare, the rising demand for medical services, compounded by a shortage of professionals, presents significant challenges. To address these issues, the healthcare industry has turned to artificial intelligence (AI) to enhance various services such as disease diagnosis, medical imaging interpretation, clinical laboratory tasks, screenings, and health communications. By offering real-time, human-like interactions, AI-driven chatbots facilitate access to healthcare information and services, aiding symptom analysis and providing preliminary disease information before professional consultations. This initiative aims not only to reduce healthcare costs but also to enhance patient access to medical data. Despite their growing popularity, AI-enabled chatbots or conversational agents chatbots in the healthcare disease diagnosis domain continue to encounter obstacles such as a limited user adoption and integration into healthcare systems. This study addresses a gap in the existing literature on the adoption of AI enabled healthcare disease diagnosis chatbots by analysing the elements that influence users' behavioural intention to utilize AI-enabled disease diagnosis chatbots. Employing the extended Unified Theory of Acceptance and Use of Technology (UTAUT2) as a theoretical framework, this quantitative study began with exploratory research to define its scope and context, followed by a survey of 130 participants. The study utilized multiple linear regression and Pearson correlation analysis to evaluate the data. The outcomes suggest that performance expectancy, habits, social influence, and trust significantly associated with the individuals’ behavioural intentions to use AI-enabled chatbots for disease diagnosis. The results of this study reveal that performance expectancy, habits, social influence, and trust significant association with intention to use AI-enabled chatbots for disease diagnosis. The outcomes of this study contribute to existing knowledge in information systems, particularly identifying key factors that boost user adoption of AI-enabled chatbot applications for disease diagnosis. These insights can guide system designers, developers, marketers, and promotors involved in developing, revamping, and promoting chatbot applications, considering the influential factors discovered in this research, thereby increasing the usage of chatbot apps. Furthermore, the research model developed here could serve as a valuable model for future studies on disease diagnostic chatbot applications.

Parkinson's disease (PD) is a neurodegenerative disease that affects motor abilities with increasing severity as the disease progresses. Traditional methods for diagnosing PD require specialists scoring qualitative symptoms using the motor subscale of the Unified Parkinson's Disease Rating Scale (UPDRS-III). Using force-plate data during quiet standing (QS), this study uses machine learning to target the characterization and prediction of PD and UPDRS-III. The purpose of predicting different subscores of the UPDRS-III is to give specialists more tools to help make an informed diagnosis and prognosis. The classification models employed classified PD with a sensitivity of 87.5% and specificity of 83.1%. Stepwise forward regression indicated that features correlated with base of support were most useful in the prediction of head rigidity (r-square = .753). Although there is limited data, this thesis can be used as an exploratory study that evaluates the predictability of UPDRS-III subscores using QS data. Similar prediction models can be implemented to a home setting using low-cost force plates as a novel telemedicine technique to track disease progression.

Thesis (MCur)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Background: Coronary artery disease is a form of cardiovascular disease (CVD) which manifests itself in three ways: angina pectoris, acute coronary syndrome and cardiac death. Thirty-three people die daily of a myocardial infarction (cardiac death) and 7.5 million deaths annually are caused by CVD (51% from strokes and 45% from coronary artery disease) worldwide. Globally, the CVD death rate is a mere 4% compared to South Africa which has a 42% death rate. It is predicted that by the year 2030 there will be 25 million deaths annually from CVD, mainly in the form of strokes and heart disease. The WHO compared the death rates of high-income countries to those of low- and middle-income countries, like South Africa, and the results show that CVD deaths are declining in high-income countries but rapidly increasing in low- and middle-income countries. Although there are several risk prediction tools in use worldwide, to predict ischemic risk, South Africa does not use any of these tools. Current practice in South Africa to diagnose acute coronary syndrome is the use of a physical examination, ECG changes and positive serum cardiac maker levels. Internationally the same practice is used to diagnose acute coronary syndrome but risk assessment tools are used additionally to this practise because of limitations of the ECG and serum cardiac markers when it comes to NSTE-ACS. Objective: The aim of this study was to systematically appraise evidence on the accuracy of acute coronary syndrome risk prediction tools in adults. Methods: An extensive literature search of studies published in English was undertaken. Electronic databases searched were Cochrane Library, MEDLINE, Embase and CINAHL. Other sources were also searched, and cross-sectional studies, cohort studies and randomised controlled trials were reviewed. All articles were screened for methodological quality by two reviewers independently with the QUADAS-2 tool which is a standardised instrument. Data was extracted using an adapted Cochrane data extraction tool. Data was entered in Review Manager 5.2 software for analysis. Sensitivity and specificity was calculated for each risk score and an SROC curve was created. This curve was used to evaluate and compare the prediction accuracy of each test. Results: A total of five studies met the inclusion criteria of this review. Two HEART studies and three GRACE studies were included. In all, 9 092 patients participated in the selected studies. Estimates of sensitivity for the HEART risks score (two studies, 3268 participants) were 0,51 (95% CI 0,46 to 0,56) and 0,68 (95% CI 0,60 to 0,75); specificity for the HEART risks score was 0,90 (95% CI 0,88 to 0,91) and 0,92 (95% CI 0,90 to 0,94). Estimates of sensitivity for the GRACE risk score (three studies, 5824 participants) were 0,03 (95% CI0,01 to 0,05); 0,20 (95% CI 0,14 to 0,29) and 0,79 (95% CI 0,58 to 0,93). The specificity was 1,00 (95% CI 0,99 to 1,00); 0,97 (95% CI 0,95 to 0,98) and 0,78 (95% CI 0,73 to 0,82). On the SROC curve analysis, there was a trend for the GRACE risk score to perform better than the HEART risk score in predicting acute coronary syndrome in adults. Conclusion: Both risk scores showed that they had value in accurately predicting the presence of acute coronary syndrome in adults. The GRACE showed a positive trend towards better prediction ability than the HEART risk score. / AFRIKAANSE OPSOMMING: Agtergrond: Koronêre bloedvatsiekte is ‘n vorm van kardiovaskulêre siekte. Koronêre hartsiekte manifesteer in drie maniere: angina pectoris, akute koronêre sindroom en hartdood. Drie-en-dertig mense sterf daagliks aan ‘n miokardiale infarksie (hartdood). Daar is 7,5 miljoen sterftes jaarliks as gevolg van kardiovaskulêre siektes (51% deur beroertes en 45% as gevolg van koronêre hartsiektes) wêreldwyd. Globaal is die sterfte syfer as gevolg van koronêre vaskulêre siekte net 4% in vergelyking met Suid Afrika, wat ‘n 42% sterfte syfer het. Dit word voorspel dat teen die jaar 2030 daar 25 miljoen sterfgevalle jaarliks sal wees, meestal toegeskryf aan kardiovaskulêre siektes. Die hoof oorsaak van sterfgevalle sal toegeskryf word aan beroertes en hart siektes. Die WHO het die sterf gevalle van hoeinkoms lande vergelyk met die van lae- en middel-inkoms lande, soos Suid Afrika, en die resultate het bewys dat sterf gevalle as gevolg van kardiovaskulêre siekte is besig om te daal in hoe-inkoms lande maar dit is besig om skerp te styg in lae- en middel-inkoms lande. Daar is verskeie risiko-voorspelling instrumente wat wêreldwyd gebruik word om isgemiese risiko te voorspel, maar Suid Afrika gebruik geen van die risiko-voorspelling instrumente nie. Huidiglik word akute koronêre sindroom gediagnoseer met die gebruik van n fisiese ondersoek, EKG verandering en positiewe serum kardiale merkers. Internationaal word die selfde gebruik maar risiko-voorspelling instrumente word aditioneel by gebruik omdat daar limitasies is met EKG en serum kardiale merkers as dit by NSTE-ACS kom. Doelwit: Die doel van hierdie sisematiese literatuuroorsig was om stelselmatig die bewyse te evalueer oor die akkuraatheid van akute koronêre sindroom risiko-voorspelling instrumente vir volwassenes. Metodes: 'n Uitgebreide literatuursoektog van studies wat in Engels gepubliseer is was onderneem. Cochrane biblioteek, MEDLINE, Embase en CINAHL databases was deursoek. Ander bronne is ook deursoek. Die tiepe studies ingesluit was deurnsee-studies, kohortstudies en verewekansigde gekontroleerde studies. Alle artikels is onafhanklik vir die metodologiese kwaliteit gekeur deur twee beoordeelaars met die gebruik van die QUADAS-2 instrument, ‘n gestandaardiseerde instrument. ‘n Aangepaste Cochrane data instrument is gebruik om data te onttrek. Data is opgeneem in Review Manager 5.2 sagteware vir ontleding. Sensitiwiteit en spesifisiteit is bereken vir elke risiko instrument en ‘n SROC kurwe is geskep. Die SROC kurwe is gebruik om die akkuraatheid van voorspelling van elke instrument te evalueer en te toets. Resultate: Twee HEART studies en drie GRACE studies is ingesluit. In total was daar 9 092 patiente wat deelgeneeem het in die gekose studies. Skattings van sensitiwiteit vir die HEART risiko instrument (twee studies, 3268 deelnemers) was 0,51 (95% CI 0,47 to 0,56) en 0,68 (95% CI 0,60 to 0,75) spesifisiteit vir die HEART risiko instrument was 0,89 (95% CI 0,88 to 0,91) en 0,92 (95% CI 0,90 to 0,94). Skattings van sensitiwiteit vir die GRACE risiko instrument (drie studies, 5824 deelnemers) was 0,28 (95% CI 0,13 to 0,53); 0,20 (95% CI 0,14 to 0,29) en 0,79 (95% CI 0,58 to 0,93). Die spesifisiteit vir die GRACE risiko instrument was 0,97 (95% CI 0,95 to 0,99); 0,97 (95% CI 0,95 to 0,98) en 0,78 (95% CI 0,73 to 0,82). Met die SROC kurwe ontleding was daar ‘n tendens vir die GRACE risiko instrument om beter te vaar as die HEART risiko instrument in die voorspelling van akute koronêre sindroom in volwassenes. Gevolgtrekking: Altwee risiko instrumente toon aan dat albei instrumente van waarde is. Albei het die vermoë om die teenwoordigheid van akute koronêre sindroom in volwassenes te voorspel. Die GRACE toon ‘n positiewe tendens teenoor beter voorspelling vermoë as die HEART risiko instrument.

Thesis (MPhil)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Voluntary Counseling and Testing (VCT) is considered an important component of the South African government’s response to the HIV/AIDS pandemic. Despite of this, the numbers of South Africans who have accessed VCT remains low. Pregnant women in antenatal clinics remain the primary recipients of HIV testing since it is routinely offered to them at antenatal clinics. Figures from antenatal clinics constitute the most important source of HIV/AIDS statistics in South Africa. Targeting women at antenatal clinics perpetuate the stereotypes that women are solely responsible for reproductive health issues or, that they are to be blame for the mounting HIV infections. These beliefs exacerbate the culminating violence against women. According to observation, active involvement of male youth in reproductive health at the Rosedale Clinic situated in Uitenhage, a town in the Eastern Cape, appears to be very limited. This might be as a result of traditional beliefs declaring reproductive health a primarily female domain. Active involvement of males in reproductive health is considered to have positive health outcomes both for themselves, and their partners. The purpose of this study is thus to encourage males served by the Rosedale clinic to become more actively involved in one aspect of reproductive health, namely voluntary counseling and testing (VCT). The study aims to find out which factors constitute barriers and enablers to VCT acceptance by male youth. Semi-structured, face-to- face interviews were conducted in September 2006 with eighteen males, 18 to 25 years, to determine from their perspective what constitute barriers and enablers to HIV test acceptance by males. These participants were recruited from two well-known rugby clubs in Uitenhage, located in the Eastern Cape. In addition, a focus group discussion was conducted with four males recruited at a graduate development programme hosted in Uitenhage in order to explore common themes emerging from interviews and the discussion. A pervasive, psychologically rooted fear; and possible low perception of risk emerge from this study as main barriers to HIV testing. Negative perceptions regarding service delivery in the public health sector constitute another barrier to HIV testing. The possibility of teasing, a common phenomenon amongst rugby players but not exclusive to them, exacerbates peer pressure thus possibly contributing to low levels of HIV test acceptance among these males. Increased HIV test acceptance is associated with increased opportunities of exposure to HIV testing opportunities, for example at awareness campaigns. Access to medical aid and income is also associated with an increased likelihood of HIV testing since most males prefer accessing HIV testing services in the private sector. Convenience and ease of access to HIV testing services are important when these males consider going for HIV testing. / AFRIKAANSE OPSOMMING: Vrywillige Berading en MIV Toetsing, een aspek van reproduktiewe gesondheid, word beskou as ‘n belangrike komponent van die Suid-Afrikaanse regering se strategie teen MIV/VIGS. Ongeag van hierdie feit is ‘n groot aantal Suid-Afrikaners nog nie getoets vir MIV nie. Swanger vrouens word op ‘n daaglikse basis hierdie toets aangebied as deel van roetine ondersoeke. Syfers vanaf pre-natale klinieke vorm die hoofbron van Suid- Afrika se HIV/VIGS statistieke. Die feit dat swanger vrouens die hoofteikengroep is vir MIV toetsing dra by tot stereotipes wat daartoe lei dat vrouens primêr verantwoordelik is vir die behoud van reproduktiewe gesondheid; en dat hulle beskou word as die hoofverdagtes in die toenemende oordrag van MIV. Laasgenoemde beskuldiging vererger geweld teen vrouens. Volgens waarneming by Rosedale publieke kliniek geleë in Uitenhage, ‘n dorp in die Oos-kaap, is veral jeugdige mans se betrokkenheid in reproduktiewe gesondheid uiters minimaal. Dit kan moontlik wees omdat reproduktiewe gesondheid tradisioneel as ‘n vroulike domein beskou word. Aktiewe betrokkenheid van beide mans en vrouens in reproduktiewe gesondheid het positiewe gesondheidsuitkomste vir beide partye tot gevolg. Die doel van hierdie studie is dus om jongmans wie deur die Rosedale kliniek bedien word aan te moedig om meer sigbaar te word in reproduktiewe gesondheidskwessies; met die oog op een aspek daarvan naamlik, vrywillige berading en MIV toetsing. Die studie poog dus om uit te vind watter struikelblokke jeugdige mans weerhou van MIV toetsing en; watter faktore mans aanmoedig om vir die toets te gaan. Semi-gestruktureerde, aangesig-tot- aangesig onderhoude is in September 2006 met 18 mans, vanaf die ouderdomme 18 tot 25 jaar, gevoer. Hierdie mans was tydens die studie rugbyspelers vanuit twee welbekende rugbyklubs op die dorp. ‘n Addisionele fokus groep is verder gevoer met manlike studente wie ten tye van die studie aan ‘n ontwikkelingsprogram vir gradueerders deelgeneem het op die dorp. Hierdie fokusgroep is geloods om soortgelyke temas vanuit die onderhoude en die bespreking te ondersoek. Die studie toon dat ‘n diepgewortelde, sielkundige vrees; en moontlike lae bewustheid van persoonlike risiko die twee vernaamste struikelblokke is vir MIV toetsing. Negatiewe sienings rakende die publieke gesondheidssektor kan moontlik bydrae tot weerstand teen MIV toetsingsdienste. Tergery, ‘n bekende verskynsel onder rugbymans, maar nie slegs beperk tot diè groep nie, dra by tot groepsdruk en weerhou moontlik menige mans van MIV toetsing. Diegene in die studie wie alreeds vir MIV getoets is geniet toenemende blootstelling aan MIV toetsingsgeleenthede; bv tydens bewusmakingsveldtogte geloods òf by die werk òf tersiêre instellings. Toegang tot ‘n mediese fonds; en ‘n inkomste is moontlike bepalende faktore sienende dat meeste respondente gesondheidsdienste in die privaatsektor verkies. Gerieflike toegang tot MIV toetsingsdienste word deur sommige mans as belangrike beskou wanneer hulle MIV toetsing oorweeg.