Biostatistics

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    Assessment of different methods of determining confidence intervals for the difference of binomial proportions
    (University of the Free State, 1998-05) Nel, Mariette; Joubert, G.; Schall, R.; Nel, D. G.
    Abstract not available
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    Cultural competence among occupational therapy students at the University of the Free State, South Africa
    (University of the Free State, 2012) Janse van Rensburg, Elize; Van der Merwe, Tania; Nel, Mariette
    English: The study investigates occupational therapy students’ perceptions about cultural competence and assessed their levels of competence to determine whether the undergraduate occupational therapy curriculum at the University of the Free State sufficiently equips students to become culturally competent professionals. A descriptive study was undertaken, using a non-standardised questionnaire. Students did not feel sufficiently equipped regarding cultural competence, and their levels of competence ranged between cultural incapacity and pre-competence. The results support students’ perceptions that the current occupational therapy curriculum at the University of the Free State does not sufficiently equip them to become culturally competent.
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    An online multiple-choice microbiology game for undergraduate medical students: a case study
    (University of the Free State, 2012) Struwig, Daleen; Beylefeld, Adri; Hugo, Alwyn; Joubert, Gina
    English: Educational games are increasingly used in medical curricula to enhance the process of mastering subject content. Students experience medical microbiology as an exceptional challenge because of unfamiliar terminology and the extensive volume of this field of study. Consequently, many students believe that medical microbiology could be a major contributor to failing an academic year. This article describes the use of an online multiple-choice game to improve students’ performance in the Infections module of their medical training programme. The results show that an informal approach to learning may be beneficial to students, even in tertiary institutions.
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    Profile of clinical trial biostatisticians and university courses to train them in South Africa
    (University of the Free State, 2003-11) Rossouw, Sharon Lynne; Joubert, G.; Schall, R.
    English: Many statistical issues in the area of clinical trials are specific to this particular field. A clinical trial biostatistician should not only be appropriately qualified in general statistical theory, but also be appropriately trained and experienced in the application of statistics to clinical trials. This thesis investigates the background and training of statisticians practicing in this field in South Africa. It provides an overview of the training that is available for clinical trial biostatisticians at universities in South Africa. Lastly, the thesis also provides recommendations for the training and development of clinical trial biostatisticians. The methodology used for this research included a literature study regarding the required profile (education/training, years of experience and part of the industry in which they are employed) of a clinical trial biostatistician, and topics of interest to such a biostatistician. A review of the content of statistics courses offered at South African Universities was performed. A questionnaire survey was conducted to assess the education/training profile of clinical trial biostatisticians in South Africa and to assess the knowledge of biostatisticians in areas considered necessary to be an appropriately qualified and experienced clinical trial biostatistician as defined in the literature. Twenty-nine respondents were considered valid clinical trial biostatisticians and were thus included in the analysis of the clinical trial biostatistician questionnaires. Twenty South African universities were approached to provide information regarding the statistics courses they present. Information was obtained from fourteen (70.0%) of these universities. The profile of clinical trial biostatisticians in South Africa, with respect to qualifications and experience, is comparable to clinical trial biostatisticians in Europe. However, the industries in which the biostatisticians are employed differ from those that employ clinical trial biostatisticians in Europe. South African clinical trial biostatisticians are not necessarily familiar with all the topics applicable to their discipline. The areas in which they were the least familiar were: regulatory requirements and international guidelines, statistical analysis considerations, reporting, and quality control and documentation. Aside from statistical methods which were mostly learned at university, knowledge and experience were mostly acquired through on-the-job training followed by self-study and reading. It is hoped that the implementation of a university programme specific to clinical trial biostatisticians, improvements in current statistical courses, the development of a clinical trial biostatistician manual and the introduction of a medical statistician certification scheme, would contribute to developing what Iman (1995) is referring to when he quotes Kettenring in saying, "Industry needs holistic statisticians who are nimble problem solvers".
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    A profile of statistics and research training of undergraduate medical students at South African universities
    (University of the Free State, 2005-12) Dommisse, Jean; Joubert, G.
    English: Statistics and research methodology are important components of a medical curriculum, since statistical analysis features in the majority of research papers published in medical journals. Medical practitioners need a basic understanding and knowledge of statistics and research principles. Evidence Based Medicine has given an enormous opportunity for statisticians to teach critical appraisal, and to orientate future doctors towards evidence-based practice. Literature on the teaching of statistics and research methodology are available for the United Kingdom, United States and elsewhere in the world but not for South Africa. It is therefore important to do this study on the profile of research methodology and statistics training for undergraduate medical students at South African universities in terms of the following: (1) What subjects (topics) are medical students taught? (2) Who does the teaching? (3) When is the learning programme / contact sessions taught during the medical students’ curriculum? (4) How is the learning programme / contact sessions taught to the students? I contacted the heads of the eight medical schools in South Africa via email to ask them whether they would give consent for the university to participate in my study. Thereafter I contacted the relevant persons of all the medical schools via email and asked them if they were willing to participate. They needed to complete a questionnaire and checklist. The checklist covered topics taught and the questionnaire the other research questions. The checklist and questionnaire were compiled based on the literature, and tested in a pilot study. One university did not respond, one university does not teach a formal Biostatistics course, one does the Biostatistics course as an elective programme and 5 universities teach the Biostatistics course during the medical curricula. Seven universities completed a checklist and six universities completed the questionnaire. I also requested the learning programme material from the universities to see what the aims and objectives of their courses are. Five universities supplied me with their learning program materials. In South Africa the specific statistics or research methodology courses show a vast variety of implementation dates at the different universities. Only one university reinforced the course during the 3rd and 5th year, after it had been taught during the 1 st year. For the other, 4 universities teac h the course in the 1st year, 1 in the 2nd year and 1 in the 3rd or 4th year, depending on when it is selected as an elective programme. The class sizes vary from 40 to 320 students. Four universities use practical classes and 3 universities use tutors. Three universities use research projects during their medical education. Five of the universities expose the students to Excel, directly in practical classes and indirectly through the research projects that the students must do. The aims and objectives of the South African universities seem on par with what is proposed in the literature. The persons responsible for the teaching of the statistics / research methodology courses are a doctor (2 universities), statistician (6 universities) and Applied Mathematics lecturer (1 university). The following topics are taught to the medical students at most universities in South Africa: (1) Study designs in medical research. (2) Exploring and presenting data. (3) Summarising data. (4) Probability. (5) Sampling. (6) Statistical inference. (7) Analysis of cross tabulation. (8) Critical reading. Four universities teach the topic “From sample to population”, “Analysis of the means of small samples”, scatter diagrams and correlations. Only three universities teach the topic of regression. Survival ana lysis and multiple comparisons are not seen as a core topic in the medical curricula. Recommendations are made for inclusion of topics in the courses, and for future studies in this field.
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    Randomised placebo-controlled trial to evaluate the effect of vitamin A on mother-to-child transmission of HIV-1 in Bloemfontein
    (University of the Free State, 2002-11) Chikobvu, Perpetual; Joubert, G.; Schall, R.; Van der Ryst, E.
    English: Mother-to-child (vertical) transmission is the primary means by which young children acquire human immunodeficiency virus type 1 (HIV -1) infection. Anti-retrovirals such as Zidovudine and nevirapine can reduce vertical transmission of HIV significantly, but this treatment is still largely unaffordable in Africa. Maternal vitamin A deficiency is suspected to enhance vertical transmission of HIV. Furthermore, vitamin A is known to act as a coenzyme to the immune process. Therefore, a double-blind randomized placebo controlled trial to assess the effect of vitamin A supplementation on vertical transmission of HIV was launched in Bloemfontein in 1997. A total of 2949 pregnant women attending the antenatal clinics at Pelonomi and Universitas hospitals and the Mangaung University Community Partnership clinic were counselled for HIV testing, and 2543 were willing to be screened by HIV testing for possible inclusion in the trial. Of the women screened 595 (23.4%) were HIV positive, and 303 of these were willing to participate in the trial. 152 women were randomized to vitamin A treatment and 151 to placebo treatment. Patients were seen at 2 monthly intervals in the antenatal phase. Post-natally mother-infants pairs were seen when the infant was 1 month old, 3 months old, and thereafter, 3 monthly till 18 months old. A total of 191 patients (63% of all the study participants) missed one or more visits and had to be traced. Of the 303 patients included in the study 158 had a conclusive infant HIV test result (patients in the Intention To Treat (!TT) analysis population) and 104 patients had a conclusive infant mv test result when the baby was 3 months old (patients in the Per Protocol (PP) analysis population). Of 158 patients, in the ITT population 73 were in the vitamin A group and 85 in the placebo group. Per treatment group the baseline characteristics of those in the IIT population and those who are not, did not differ significanti y. The mv transmission rates were 19.2% and 21.2% for vitamin A and placebo groups respectively (IIT population). There is no statistically significant difference in the transmission rates between vitamin A and placebo groups (p=0.76). Overall, this study provides no evidence that vitamin A is effective in reducing vertical mv-1 transmission rate. There was no statistically significant difference in the percentages of mv symptoms recorded at post delivery visit 1 through to the 18 months visit between the two treatment groups for either mothers or infants. A similar pattern was observed for the vital signs for the mothers. The full blood and T-cell counts were similar between the two treatment groups at all visits for both mothers and infants. Only 4 patients reported adverse events; these were not related to the treatment. Twenty six infants and one mother died during the study. The overall infant mortality rate was 85.8 per 1000 infant population. The infant death rates were approximately 11% in the placebo group and 6% in the vitamin A group (p=0.097). Thus, Vitamin A was associated with a reduction in infant mortality, although not statistically significant. This association may be worth further investigation as there is potential for a substantial impact.