1,721,116 research outputs found
Epidemiological research methods. Part III. Randomised controlled trials (for interventions)
Full text linkCITATION: Botha, J. L. & Yach, D. 1987. Epidemiological research methods. Part III. Randomised controlled trials (for interventions). South African Medical Journal, 71:657-660.The original publication is available at http://www.samj.org.zaOnce the magnitude and distribution of a health problem
and its possible determinants have been established, anempts
to prevent, treat, or control the problem by intervening on one
or more of the determinants should be made.Publisher’s versio
Epidemiological research methods. Part I. Why epidemiology?
Full text linkCITATION: Yach, D. & Botha, J. L. 1986. Epidemiological research methods. Part I. Why epidemiology? South African Medical Journal, 70:267-270.The original publication is available at http://www.samj.org.zaIn the first article in a series on epidemiological research
methods, we describe the origins and uses of epidemiology and
introduce the different types of epidemiological study design.Publisher’s versio
Epidemiological research methods. Part IV. Case-control studies
Full text linkThe original publication is available at http://www.samj.org.zaCITATION: Yach, D. & Botha, J. L. 1987. Epidemiological research methods. Part IV. Case-control studies. South African Medical Journal, 71:763-766.Randomised controlled trials (RCTs), although regarded as
the best method for assessing the efficacy of an intervention, have several shoncomings and may be impossible to conduct,
for example in the case of harmful risk factors or aetiological
factors such as smoking4 or schistosomes. Analytical studies such as case-eontrol studies or non-RCT follow-up studies provide alternative approaches for assessing drug or vaccine efficacy, health service8 interventions, as well as the role of risk factors for disease.South African Medical JournalPublishers' Versio
Epidemiological research methods. Part VI. Planning a research project
Full text linkCITATION: Botha, J. L. & Yach, D. 1987. Epidemiological research methods. Part VI. Planning a research project. South African Medical Journal, 72:563-566.The original publication is available at http://www.samj.org.zaThe need for writing a good
protocol is still paramount and applies not only to randomised
controlled trials (RCTs), but to all research projects. Writing a
good protocol reflects good planning, and in this paper we
address some vital aspects of planning a study and writing a
protocol. The information given here should be augmented by
referring to earlier articles in this series, as well as guidelines
published elsewhere.Publisher’s versio
Epidemiological research methods. Part V. Follow-up studies
Full text linkCITATION: Yach, D. & Botha, J. L. 1987. Epidemiological research methods. Part V. Follow-up studies. South African Medical Journal, 72:266-269.The original publication is available at http://www.samj.org.zaFollow-up studies (also called prospective or cohort studies)
are used to determine the natural history of disease, to evaluate
the role of risk factors in causation or association, to determine
the prognosis of patients with existing disease, and to evaluate
the role of drugs and other interventions in preventing disease
or further complications. In follow-up studies sampling is
prospective, because individuals are· followed up to see whether
they develop the outcome of interest. These studies have
become increasingly important in recent decades with the
epidemiological transition that has paralleled population
development from a high incidence of acute infectious diseases
to a high ipcidence of chronic, non-infectious diseases in
ageing populations.Publisher’s versio
Epidemiological research methods. Part VII. Epidemiological research in health planning
Full text linkCITATION: Yach, D. & Botha, J. L. 1987. Epidemiological research methods. Part VII. Epidemiological research in health planning. South African Medical Journal, 72:633-636.The original publication is available at http://www.samj.org.zaThe goal of epidemiology is to improve the health status of
human populations. In our series thus far we have srressed
the need to use the correct design for epidemiological studies,
a sampling scheme that yields interpretable results, measurements
that are both valid and reliable, and finally the appropriate
analysis. These methodological considerations are of
importance if the goal is to be reached. In this article we
assume that most of these issues have been adequately dealt
with and focus on how the results of epidemiological research
can be used by health planners to improve the health status of
regions and the country as a whole.Publisher’s versio
Epidemiological research methods. Part II. Descriptive studies
Full text linkCITATION: Botha, J. L. & Yach, D. 1986. Epidemiological research methods. Part II. Descriptive studies. South African Medical Journal, 70:766-772.The original publication is available at http://www.samj.org.zaIn a descriptive study, therefore, the magnitude and distribution of a health problem in a specified population is studied in terms of TIME (when did it occur?), PLACE (where did it occur?) and PERSON (which groups are affected?). The design starts with an idea that occurs to the researcher about a particular problem. This is followed by selecting a group of individuals to be studied (sampling), considering which attributes to measure (measurement), describing the findings, and finally drawing conclusions on the basis of the findings. Commonly, new ideas or hypotheses are generated in this final stage, usually regarding possible explanations for the health problems described (cause-effect relationships). Such relationships may be attempts to explain the aetiology of diseases or the effect of preventive, curative or rehabilitative measures. Important issues affecting the reliability of the sampling and measurement processes are discussed, some descriptive statistical measures demonstrated and how conclusions are affected by these, are indicated.Publisher’s versio
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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