After duplicates and overlaps were deleted, the abstracts of returned references were read. A number of these references were excluded based on the following criteria: literature on intellectual disability in Africa but not South Africa (e.g., Nigeria); literature on disability in South Africa but not intellectual disability (e.g., hearing impairment); literature on frequently co-occurring presentations of which intellectual disability is not necessarily included by definition (e.g., intellectual disability in Down’s Syndrome as included versus FAS without intellectual disability as excluded); and irrelevant database returns (e.g., South Carolina,
38
Southern Australia). Etiological studies on, for example, nutritional insufficiency (e.g., iodine or iron insufficiency, suboptimal nutrition, maternal or perinatal malnutrition), infectious illnesses (e.g., tuberculous meningitis), parasitic or tropical diseases (e.g., measles, polio, bacterial meningitis, malaria, encephalitis, or helminth infectionscaused by different species of parasitic worms transmitted by eggs present in human faeces which contaminate the soil in areas where sanitation is poor – see Kvalsvig & Albonico, 2013), and vulnerabilities in preterm or low birth weight infants were excluded unless the topic of study was intellectual disability. Returned and subsequently excluded sources are offered, with help from the seven independent raters, in Table 3.1 in Part 2 of this review (Chapter 3).
2.2.4. Independent raters
Up to this point, a total of 1054 sources were returned after the first search with original Boolean syntax and MeSH entry terms. After collating, cross-referencing, and deleting duplicates returned from all the databases, 539 sources remained. The abstracts of these returned references were read, resulting in the first exclusions as explained above. After this first exclusion sweep, the remaining references were investigated for forward citations. The reference lists of all peer reviewed journal articles as well as those of the “grey literature” were studied for inclusion of possible further references that might meet the inclusion criteria, but perhaps missed by the initial search (resulting in the inclusion of a further eight studies). This left a possible 233 articles, chapters, papers, or studies for inclusion in the review. At this point, the help of independent raters was sought for a second sweep to verify whether the remaining selected articles indeed address the review question and thus meet the criteria for inclusion of a review of literature published on intellectual disability in South Africa over the past 26 years (1989-2015). These raters will also be involved in the systematic review that will develop from the literature review offered here. The following individuals with
experience in the field of intellectual disability in South Africa were approached and agreed to act as independent raters: Colleen Adnams (CA), Judith McKenzie (JM), Ockert Coetzee (OC), Manny Saptouw (MS), Andrew Hooper (AH), Lameze Abrahams (LA), and Leslie Swartz (LS). Each rater was allocated up to 29 articles, chapters, papers, or studies to review for inclusion. Five raters returned their rater forms, and I reviewed the remaining material. As far as possible, raters were matched with references particular to their field of expertise and experience in intellectual disability in South Africa.
39
Each rater was furnished with a specifically selected set of Independent Rater Forms, their particular reference list, and copies of the corresponding literature. The Independent Rater Forms contained each paper’s abstract, and were organised according to first author surnames in alphabetical order. The rater’s initials (together with the list number of each particular paper) served as a code that corresponds with the author and title of the papers in the rater’s reference list, rater forms, and the provided literature for inclusion review. For example, an entry in Judith McKenzie’s Independent Rater Forms would have look like this (Appendix A of this chapter):
JM14 Kromberg, J., Zwane, E., Manga, P., Venter, A., Rosen, E., & Christianson, A. (2008). Intellectual disability in the context of a South African population.
Journal of Policy and Practice in Intellectual Disabilities, 5(2), 89-95.
doi:10.1111/j.1741-1130.2008.00153.x
Provided for review as: JM14 Kromberg et al. 2008.pdf
As per the literature review’s inclusion criteria, raters were asked whether the study, chapter, paper, or article is about intellectual disability; whether it is about intellectual disability in South Africa; and whether it was published between 1989 and 2015. In cases where hand searches did not produce a required study, authors of the included literature were contacted for their papers via ResearchGate or a librarian at the University of Stellenbosch was approached for help. “Missing” papers were sent on to raters as they became retrievable. Completed and returned Independent Rater Forms were safely stored as representative of the review methodology.
2.3. RESULTS
Of the 233 articles, chapters, papers, or studies sent to the independent raters, 163 sources were retained. Table 3.1 in Chapter 3 offers the 70 references that were identified for
exclusion in the review of literature on intellectual disability in South Africa published over the past 26 years (1989-2015). Figure 2.1 summarises this process:
Collating returns
Cross-referencing Independent Raters Duplicates deleted
70 (excluded)
1054 539 233
40
“Sweep 1” “Sweep 2”
Figure 2.1. Application of inclusion and exclusion criteria
From an average of six to seven articles published per year over the past 26 years on intellectual disability in South Africa, it became possible to organise the included peer reviewed and “grey” literature around the following identified themes: historic turns in the research literature indicative of shifts in research and nomenclature (some authors have also made contributions over large time spans); epidemiology, services, policy, and interventions; aetiology and co-morbidity; the socio-economics of intellectual disability in South Africa; intellectual disability and children; and intellectual disability and adults. Linking to the chapter on future research offered in Chapter 8, some opportunities for further investigation are also mentioned toward the end of this review.