Department of Statistics & Population Studies
Permanent URI for this community
Browse
Browsing by Title
Now showing 1 - 20 of 141
Results Per Page
Sort Options
Item A high incidence of serious life-threatening cardiovascular medical encounters during a marathon (2014–2019) calls for prevention strategies: SAFER XL(Taylor and Francis Ltd., 2024) Jordaan, Esmè; Green, Darren; Sewry, Nicola; Derman, WayneObjective: The aim of this study was to determine the incidence and nature (severity and type by organ system and specific diagnosis) of all medical encounters (MEs), including serious/life-threatening MEs (SLMEs) during a South African road marathon. Methods: This descriptive study was a retrospective analysis of data collected over 6 years at the Cape Town Marathon from 2014 to 2019, which included 40 446 starters. All MEs were collected and described as per the consensus statement for mass community-based sporting events. Incidences (I; per 1000 starters; 95% CI) are described for all MEs, SLMEs, and by organ system and specific diagnosis. Results: The incidence of all MEs was 8.7 (95% CI: 7.8–9.6) per 1000 starters. The largest contributor to all MEs, by organ system affected, was cardiovascular-related, with an incidence of 1.8 (95% CI: 1.4–2.2), where exercise-associated postural hypotension was the most common specific diagnosis (I = 1.3; 95% CI: 1.0–1.7). The incidence of all SLMEs was 1.0 (95% CI: 0.7–1.4) making up 11.7% (41/350) of all MEs. The incidence of SLMEs by organ system was highest in the cardiovascular system (I = 0.4; 95% CI: 0.3–0.7), with acute coronary syndrome (ACS) (I = 0.2; 95% CI: 0.1–0.4) the most common specific diagnosis. There were no sudden cardiac deaths (SCD) nor sudden cardiac arrests (SCA). Conclusion: There was a high proportion of cardiovascular-related medical encounters, as well as SLMEs. We recommend that event organizers and race medical directors investigate prevention strategies to mitigate against risk of SLMEs, specifically acute cardiovascular SLMEs.Item African female migrants and housing acquisition in South Africa: A comparison between 2001 and 2011 Population Census(University of Western Cape, 2021) Mokabati, Koketso Percy; Nsengiyumva, PhilomeneAfrican female migrants make up a large portion of the population in general and in South Africa in particular. This includes both the documented and the undocumented female migrants. Nonetheless, they are confronted with a housing challenge in the countries of destination. This study seeks to examine the types of housing, the methods of housing acquisition, and the size of housing that African female migrants have access to. This study used secondary data of the 2001 and 2011 Population Censuses, gathered from the (Statistics South Africa (Stats SA) database to look into African female migration and housing acquisition in South Africa. The study used the Chi-square test statistic to measure the relationship between the variables of interest.Item The AIDS transition: Impact of HIV/ AIDS on the demographic transition of black/ African South Africans by 2021(University of Western Cape, 2004) Matanyaire, Sandra D.; Shell, R.C.-H.The first two official AIDS cases were diagnosed in South Africa in 1982. During the same period of the 1980s, the black/ African population was experiencing an accelerated fertility decline, following a period of accelerated mortality decline. Demographers invoked the demographic transition theory to explain the observed mortality and fertility decline. According to the demographic transition theory, mortality and fertility rates would continue declining to low, post transitional levels with increasing modernization. The relatively higher prevalence of HIV/ AIDS estimated among black/ African South Africans is expected to alter their demographic transition. This research investigates the impact of HIV/ AIDS on the demographic transition of black/ Africans by 2021.Item The AIDS transition: impact of HIV/AIDS on the demographic transition of black/African South Africans by 2021(University of the Western Cape, 2004) Matanyaire, Sandra D.; Shell, Robert C.H.; Haldenwang, B.B.; Dept. of Statistics; Faculty of ScienceThe first two official AIDS cases were diagnosed in South Africa in 1982. During the same period of the 1980s, the black/African population was experiencing an accelerated fertility decline, following a period of accelerated mortality decline. Demographers invoked the demographic transition theory to explain the observed mortality and fertility decline. According to the demographic transition theory, mortality and fertility rates would continue declining to low, post transitional levels with increasing modernization. The relatively higher prevalence of HIV/AIDS estimated among black/African South Africans is expected to alter their demographic transition. This research investigated the impact of HIV/AIDS on the demographic transition of black/Africans by 2021.Item An examination of the mortality rate associated with teenage pregnancy in South Africa(SAGE Publications Ltd, 2024) Sithole, Tronic; Appunni, Sathiya SusumanThis study investigates factors contributing to teenage pregnancy in South Africa and their impact on maternal mortality. Twenty participants were purposively sampled for one-on-one interviews using a mixed-methods and descriptive study design. SPSS software analysed the data, revealing reduced risk factors through educational policies. Teenage mortality rates from pregnancy and maternal health issues are lower than the rates in adults, with high blood pressure, abortion and injuries being the leading causes of adolescent death. The study emphasises a significant public health concern in South Africa, influencing women’s life expectancy due to socioeconomic barriers and insufficient awareness of danger signs, urging prioritised policies and programmes.Item Analysis and estimation of customer survival Time in subscription-based businesses(University of the Western Cape, 2008) Mohammed, Zakariya Mohammed Salih; Kotze, Danelle; Maritz, Johannes Stefan; Dept. of Statistics; Faculty of ScienceSubscription-based industries have seen a massive expansion in recent decades. In this type of industry the customer has to subscribe to be able to enjoy the service; there-fore, well-de ned start and end points of the customer relationship with the service provider are known. The length of this relationship, that is the time from subscription to service cancellation, is de ned as customer survival time. Unlike transaction-based businesses, where the emphasis is on the quality of a product and customer acquisition, subscription-based businesses focus on the customer and customer retention. A customer focus requires a new approach: managing according to customer equity (the value of a rm's customers) rather than brand equity (the value of a rm's brands). The concept of customer equity is attractive and straightforward, but the implementation and management of the customer equity approach do present some challenges. Amongst these challenges is that customer asset metric - customer lifetime value (the present value of all future pro ts generated from a customer) - depends upon assumptions about the expected survival time of the customer (Bell et al., 2002; Gupta and Lehmann, 2003). In addition, managing and valuing customers as an asset require extensive data and complex modelling. The aim of this study is to illustrate, adapt and develop methods of survival analysis in analysing and estimating customer survival time in subscription-based businesses. Two particular objectives are studied. The fi rst objective is to rede ne the existing survival analysis techniques in business terms and to discuss their uses in order to understand various issues related to the customer-fi rm relationship. The lesson to be learnt here is the ability of survival analysis techniques to extract important information on customers with regard to their loyalties, risk of cancellation of the service, and lifetime value. The ultimate outcome of this process of studying customer survival time will be to understand the dynamics and behaviour of customers with respect to their risk of cancellation, survival probability and lifetime value. The results of the estimates of customer mean survival time obtained from different nonparametric and parametric approaches; namely, the Kaplan-Meier method as well as exponential, Weibull and gamma regression models were found to vary greatly showing the importance of the assumption imposed on the distribution of the survival time. The second objective is to extrapolate the customer survival curve beyond the empirical distribution. The practical motivation for extrapolating the survival curve beyond the empirical distribution originates from two issues; that of calculating survival probabilities (retention rate) beyond the empirical data and of calculating the conditional survival probability and conditional mean survival time at a speci c point in time and for a speci c time window in the future. The survival probabilties are the main components needed to calculate customer lifetime value and thereafter customer equity. In this regard, we propose a survivor function that can be used to extrapolate the survival probabilities beyond the last observed failure time; the estimation of parameters of the newly proposed extrapolation function is based completely on the Kaplan-Meier estimate of the survival probabilities. The proposed function has shown a good mathematical accuracy. Furthermore, the standard error of the estimate of the extrapolation survival function has been derived. The function is ready to be used by business managers where the objective is to enhance customer retention and to emphasise a customer-centric approach. The extrapolation function can be applied and used beyond the customer survival time data to cover clinical trial applications. In general the survival analysis techniques were found to be valuable in understanding and managing a customer- rm relationship; yet, much still needs to be done in this area of research to make these techniques that are traditionally used in medical studies more useful and applicable in business settings.Item Analyzing the relationship between the Gross Domestic Product (GDP) of Lesotho and manufacturing: 1997to 2007(University of the Western Cape, 2009) Mota, Likese Angelinah; Latief, A.; Dept. of Statistics; Faculty of ArtsThe study draws on secondary data from the Bureau of Statistics in Lesotho. Simple and multiple linear regression models techniques are used to analyze the relationship between the GDP of Lesotho and the GDP of manufacturing. The secondary data is analyzed using Statistical Packages for Social Sciences (SPSS) and Excel. The major finding is that there exists a strong positive linear relationship ( r = 0.986) between the GDP of Lesotho and the GDP of manufacturing. This means that every time the GDP of manufacturing increases the GDP of Lesotho does the same. Based on this finding, the study recommends that in order to improve, sustain and maintain the economic growth and to avoid further deterioration in the manufacturing industry, the manufacturing capacity must be strengthened for it to effectively deal with growing competition and rapid economic changes.Item An application of factor analysis on a 24-item scale on the attitudes towards AIDS precautions using Pearson, Spearman and Polychoric correlation matrices(University of the Western Cape, 2006) Abdalmajid, Mohammed Babekir Elmalik; Blignaut, Renette; Dept. of Statistics; Faculty of ScienceThe 24-item scale has been used extensively to assess the attitudes towards AIDS precautions. This study investigated the usefulness and validity of the instrument in a South African setting, fourteen years after the development of the instrument. If a new structure could be found statistically, the HIV/AIDS prevention strategies could be more effective in aiding campaigns to change attitudes and sexual behaviour.Item An Application of Multiple Regression in Exchange Rate Arrangements(University of the Western Cape, 2008) Ndiritu, Gachiri Charles; Kotze, D.; Dept. of Statistics; Faculty of ScienceThis project "An application of multiple regression in exchange rate arrangement" focused on the processes followed by different countries when choosing an exchange rate regime for currency stabilization. It analyses the consequences faced by emerging markets as a result of changes in volatility of developed countries’ currencies (American Dollar, Japanese Yen, EURO, British Pound and the Canadian Dollar).Item Assessing some socio-economic and demographic changes affecting the employment in the informal sector between the years 2017 and 2020(University of the Western Cape, 2024) Mkulisi, Sibusisiwe; Appunni, SathiyaIn most developing countries, the informal workforce comprises over half of the total workforce, reaching approximately 68.5% in South Africa. This category includes self-employed individuals in informal enterprises and wage workers in informal jobs. Multiple pressures, such as escalating youth unemployment, rapid urbanization, heightened migration in economically advanced provinces, and persistent financial crises, have collectively driven the growth of the informal sector during periods of economic instability in South Africa's labour market. From a socio-demographic standpoint, this study examines the structural shifts that impact informal employment. Specifically, it evaluates how socio-demographic variables such as age, gender, ethnicity, marital status, and education are related to work within the informal sector. Moreover, this research adopts a comparative approach, assessing how these variables manifest changes in informal sector employment between 2017 and 2020.Item Assessing the effect of imbalance correction through oversampling in the prediction of injury prevalence in distance runners(University of the Western Cape, 2023) Ngoto, Simcengile; Luus, RethaPrediction of injury prevalence in distance runnersItem Assessing the high-risk behaviour of first year students entering the University of the Western Cape(University of the Western Cape, 2007) Abels, Melissa Dione; Blignaut, R. J; Doctor, H. VGlobally, new HIV infections are heavily concentrated among the youth, i.e., persons aged 15-24 years old (UNAIDS, 2006b). In South Africa, the estimated national HIV prevalence was 10.4% among the youth in 2006 (Dorrington et a|.2006). The 2005-2006 national South African HIV rates ranged from 31.8o/oto39.3% among female youth and from 7.5oh to 10.1o/o among male youth (Dorrington et al. 2006; Pettifor et al. 2004; Shisana et al. 2005). UNAIDS (2006) stated that the future course of the HIV epidemic hinges on the high-risk behaviours the youth adept or maintain. The motivation for the study is to assess the high-risk behaviours that contribute to the spread of HIV and AIDS among the youth. The most influential high-risk behaviours that contribute to the spread of HIV and AIDS are unprotected sexual intercourse and having more than one sexual partner (Nattrass, 2004, Pettifor et al. 2004; Shisana et al. 2005; UYF & HSRC, 2005). Those who are in violent relationships, fear the threat of violence, which prevents them from insisting on condom use and this increases the risk of HIV infection (MacPhail & Campbell, 2001). Factors that leave the youth unable to set boundaries on when they want to have sex, what type of sex, or the use of contraception increase the risk of HIV infection. These factors include transactional sex, young age at first sex, cigarette smoking, alcohol use, drug use and suicidal behaviour (Aitken, 2005; Basile et al. 2006; Flisher et al. 1993c; Kauftnan & Stavrou, 2002; Pettifor et al. 2004; Shisana et aI.2005\. The population for this study included all full time first year students who registered at UWC for the first time in 2006 that attended the orientation week. A stratified, sequential random sample was drawn from the students attending the orientation. The Science Faculty Research Committee of UWC gave the consent to undertake the study. Informed consent was obtained from the 796 respondents and anonymity of their participation was ensured. The measuring instrument was a self-administered questionnaire. SAS package (SAS Institute Inc. 2004-2005) was used to clean the data and to do the analyses. Frequencies and percentages were provided for nominal and medians were provided for ratio scales. Rao-Scott Chi-square test was used to test the bivariate analysis between the high-risk behaviours. Multivariate logistic regression models were used to provide a clearer perspective on the effects of high-risk behaviours on non-condom use at last sexItem Assessing the high-risk behaviour of first year students entering the University of the Western Cape(University of the Western Cape, 2007) Abels, Melissa Dione; Blignaut, Renette; Doctor, V; Dept. of Statistics; Faculty of ScienceThe motivation of this study is to assess the high risk behaviors that contribute to the spread of HIV and AIDS among the youth. The most influential high risk behaviours that contribute to the spread of HIV and AIDS are unprotected sexual intercourse and having more than one sexual partner.The population for this study includes all full time first year students who registered for the first time in 2006 that attended the orientation week. A stratified, sequential random sample was drawn from the students attending the orientation.Item Assessing the quality of demographic data on age and sex collected from census 2001, General Household surveys (2004-2007), Labour Force surveys (2005-2007) and Community survey 2007 in South Africa(University of the Western Cape, 2012) Kamleu, Germaine; Tati, GabrielIn many countries, an enumeration of all household members remains the most important source of population statistics. According to Statistics South Africa, two population censuses and quite a few household surveys have taken place across the country. The quality of data recorded varies according to the operation. Despite great improvement in data collection and analysis capacities,some of the demographic data provided have not been assessed in terms of quality. The aim of this study was to ascertain the accuracy of demographic data on age and sex collected and the coverage during the population census 2001, General Household Surveys (2004 and 2007), Labour Force Surveys (2005 and 2007) and Community survey 2007 in South Africa. Two methods were applied to assess the quality of data. First, the direct method consists of checking the content and coverage (errors during enumeration, errors of exploitation, concordance in questionnaire). Second, the indirect method lies in the calculation of some indexes, age ratios,sex ratios, graphing of population pyramids and sex ratios curves. The indexes are Whipple’s index, Myer’s index and the Combined index of United Nations. Therefore, the main variables of interest are age, sex, place of residence and ethnic groups. Differentials in the quality according to declaration on age by gender, by ethnic group, by place of residence have been explored. This study has identified some variations in different indexes between 2001 and 2007 and has also evaluated the ethnic, gender and regional differentials. Comparison between indexes of each instrument has been done to measure some variations over years. Also, time-space comparisons were conducted across indexes of different instruments. The quality of data on age was better at national level compared to provincial level. Therefore, based on the measurements and patterns observed in the census and surveys data, the study has made some recommendations on the need for an integrated approach to reduce the gap and improve the quality of declarations on age and sex.Item Assessment of the potential of hospital birth records to estimate the number of births: A case study of Germiston and Nkomazi Local Municipalities(University of the Western Cape, 2020) Nhlapo, Mosidi Sarah; Stiegler, NancyThe advantage of a well-developed health information system is the significant role played by records produced by such a system beyond recording medical history of individuals. They are the foundation for birth registrations which when fully complete is an important tool for acquiring data necessary for planning and monitoring child and maternal health in a country. This study aimed to investigate the potential of hospital birth records to estimate the number of births in the country and supplement birth registrations data. Data was abstracted from public facilities where births occur in two municipalities; Germiston in Gauteng and Nkomazi in Mpumalanga for the period 2014 to 2016. Modified version of the BORN Data Quality Framework (BORN-DQF) of the Ontario Agency for Health Protection and Promotion (2016) was used to assess the contents and quality of hospital birth records.Item Being a mother and owning an informal hairdressing business in Cape Town, South Africa : a study on Congolese female migrants(University of the Western Cape, 2015) Gobile, Zizipho; Tati, GabrielThis study investigates how female migrants negotiate the tension that arises from being entrepreneurs, being mothers, and having families. It shows how entrepreneurship offers them self-emancipation but limits the time they spend raising their children and time they spend with their families, but puts them in a position to provide financially for themselves, their children, and families. The focus of the study is on Congolese female migrant and also females from few African countries. It is hypothesized that female migration and entrepreneurship negatively impacts the relationships of these females with their children and families. Data was obtained through a survey of fifty-three respondents who were conveniently selected. This took place in the Western Cape Province, taking Cape Town, Bellville, and Parow as the cities to be observed. The statistical package for social sciences was used to analyze data. The results showed that female entrepreneurship has a negative impact on their relationships with their children but to an extent improves their relationships with their families and/or partners.Item Beyond academia: a case for reviews of gray literature for science-policy processes and applied research(Elsevier, 2024) Yoshida, Yuki; O'Farrell, Patrick; Sitas, NadiaGray literature is increasingly considered to complement evidence and knowledge from peer-reviewed literature for science-policy processes and applied research. On the one hand, science-policy assessments need to consider a diversity of worldviews, knowledge types and values from a variety of sectors and actor groups, and synthesize policy-relevant findings that are salient, legitimate and credible. On the other hand, practitioners and scholars conducting applied research are affected by the time lag and biases of academic publication processes. Gray literature holds diverse perspectives informative for science-policy processes as well as practical evidence unfiltered by commercial publication processes. However, its heterogeneity has made it challenging to access through conventional means for a literature review. This paper details one endeavor within the Values Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) to review gray literature using Google’s Programmable Search Engine. In the absence of a standardized approach, we build on the limited experiential knowledge base for reviewing gray literature and report on the potential applicability of our strategy for future reviews. Gray literature review results contrast findings of our parallel review of academic literature, underlining the importance of mobilizing different knowledge bases in science-policy assessments, evidence-based practices, and applied research.Item Challenges of postgraduate students at the University of the Western Cape 2009 - 2013(University of the Western Cape, 2019) Lewis, Priscilla-Anne; Holtman, LornaIn South Africa, postgraduate education is a catalyst in national development and poverty alleviation that is widely acknowledged by the state and higher education institutions, such as the University of the Western Cape (UWC). Previously disadvantaged universities in South Africa were systematically moulded by apartheid planning and the prevailing social-economic-political order of the time. The structural legalised differences between historically white and historically black institutions created the key inequities between them. Unjust laws and institutionalised racism caused historical black universities (HBUs), such as the University of the Western Cape, also known as the University for the left, to lag behind with the intake of postgraduate students. Prior to 1994, students, who were fortunate enough to attend university, were mostly limited to studying towards an undergraduate degree, diploma or a certificate course, in the fields of teaching, nursing or law enforcement. The dawn of democracy opened up new possibilities; however, a major sphere of concern, was the need to speedily transform the education system, to make it inclusive for all. Systematically, institutions of higher learning focussed more on postgraduate education, as it was a stepping stone to improve enrolment growth research output, and collaborative partnerships, at national and international level. However, socio-economic factors, such as the lack of funding, were major constraints, as most postgraduate students were challenged to pay registration fees, or accommodation deposits, upon registration.Item A clustering smart phone users based on the digimiter survey and mobile application data(University of the Western Cape, 2023) Kuse, Buhle; Brydon, HumphreyDigimiter SurveyItem Comparing South African financial markets behaviour to the geometric Brownian Motion Process(University of the Western Cape, 2008) Karangwa, Innocent; Visser, Chris; Dept. of StatisticsThis study examines the behaviour of the South African financial markets with regards to the Geometric Brownian motion process. It uses the daily, weekly, and monthly stock returns time series of some major securities trading in the South African financial market, more specifically the US dollar/Euro, JSE ALSI Total Returns Index, South African All Bond Index, Anglo American Corporation, Standard Bank, Sasol, US dollar Gold Price , Brent spot oil price, and South African white maize near future. The assumptions underlying the Geometric Brownian motion in finance, namely the stationarity, the normality and the independence of stock returns, are tested using both graphical (histograms and normal plots) and statistical test (Kolmogorov-Simirnov test, Box-Ljung statistic and Augmented Dickey-Fuller test) methods to check whether or not the Brownian motion as a model for South African financial markets holds. The Hurst exponent or independence index is also applied to support the results from the previous test. Theoretically, the independent or Geometric Brownian motion time series should be characterised by the Hurst exponent of ½. A value of a Hurst exponent different from that would indicate the presence of long memory or fractional Brownian motion in a time series. The study shows that at least one assumption is violated when the Geometric Brownian motion process is examined assumption by assumption. It also reveals the presence of both long memory and random walk or Geometric Brownian motion in the South African financial markets returns when the Hurst index analysis is used and finds that the Currency market is the most efficient of the South African financial markets. The study concludes that although some assumptions underlying the rocess are violated, the Brownian motion as a model in South African financial markets can not be rejected. It can be accepted in some instances if some parameters such as the Hurst exponent are added.