the nutritional status of - Health Systems Trust

METHODS
2.1 COLLECTION AND SELECTION OF STUDIES/DATA
CHAPTER 2
Both published and unpublished data are included in this review. Published titles screened for inclusion were
obtained from several electronic data bases (MEDLINE, REPORTORIUM), as well as South African medical and nutrition
journals not included in these data bases. Articles, books and reports were obtained from the Ferdinand Postma
Library in Potchefstroom and its inter-library services. Unpublished manuscripts, dissertations, theses, research
reports and other documents (policy and briefing papers, technical reports, etc.) were obtained from the Medical
Research Council, several universities, Government Departments, the Health Systems Trust, UNICEF, WHO, FAO and
RDP offices, as well as individual colleagues and researchers. It is possible that, despite all these efforts, there may
be publications and reports with valuable information on nutritional status of South Africans that were missed.
After screening and selecting all available titles, some documents (especially postgraduate theses) could not be
traced and are therefore not included in the review. Literature that measured the nutritional status of patients or
subjects included in a study because of a specific disease or condition such as kwashiorkor, marasmus, diabetes or
hypertension, were not included in the review.
2.2 CODING OF DATA: COMPILATION OF TABLES
After collection of the literature, four researchers read the relevant sections and transferred the data to specially
designed coding forms for either anthropometry, biochemistry, nutrient intakes or clinical signs. At the same time,
short summaries of data pertaining to determinants of nutritional status and eating patterns were made. The
coding forms helped to stratify information for date of the study (or published date), province, randomisation of
subjects, ethnic group, urban/rural, gender, age, number of subjects, variables measured, means with standard
deviations or confidence intervals, percentage of subjects with abnormal values and reference range. These data
were then computerised and organised by computer into Tables 1-84.
Because of differences in study design, selection of subjects and presentation of results, it was not possible to
integrate and combine data on anthropometry, biochemistry and clinical signs of malnutrition in a meta-analysis.
These data are therefore summarized in separate tables. Available nutrient intake data were combined in a metaanalysis
by SANSS (1994) and are presented as such. For coding, urban and rural classification were used, as
reported by the authors. Where appropriate, for example in the prevalence of stunting in preschool children, means
from the different individual studies were calculated (without weighting of studies for numbers, etc.) and compared
with the recent national surveys. Data from these surveys (SALDRU/World Bank 1994; Department of Health 1994;
SAVACG, 1995) were included in the tables where appropriate, or given separately.
2.3 DIETARY DATA
Nutrient intake data depends to a large extent on methods used to obtain information on dietary habits and
intakes. The 24-hour recall method tends to measure lower intakes than, for example, the diet history and food
frequency questionnaire. A survey of the South African literature on dietary intakes (SANSS, 1995) showed that the
24-hour recall method was mostly used in larger surveys while the diet history or food frequency questionnaire
methods were used in smaller studies with limited numbers of subjects. Therefore, it was decided to present the
24-hour recall data separately, as explained in Chapter 3.3.1.
2.4 UNCODED DATA
Not all sources such as review papers, opinions, editorials and policy or briefing papers gave data in a form that
could be coded and included into the tables. If relevant, these were used in Chapters 4 and 5 to describe determinants
of nutritional status or mentioned in the brief discussions of the different tables.
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