Nutrition 2005;21:000 (in press)
Abstract
development of a novel nutrition screening tool for use in elderly South Africans
Charlton KE, 1,2 Kolbe-Alexander TL, 2 Nel JH. 3
1 Chronic Diseases of Lifestyle Unit, South African Medical Research Council,
2 Nutrition & Dietetics Division, School of Health and Rehabilitation Sciences, University of Cape Town
3 UCT/MRC Research Unit for Exercise Science and Sports Medicine, University of Cape Town and
4 Department of Logistics, University of Stellenbosch, South Africa.
Address for correspondence: Karen E. CharltonChronic Diseases of Lifestyle Unit, Medical Research Council, P.O. Box 19070, Tygerberg 7505, South Africa.
Tel: +27-21-938 0345; Fax: +27-21-933 5519; Email: w.scott@iafrica.com
Objectives: To develop a nutrition screening tool for use in older South Africans.
Design: A cross-sectional validation study in 283 free-living and institutionalized black South Africans (60 + years).
Methods: Trained fieldworkers administered a 24-hour recall and the Mini Nutritional Assessment (MNA) screening tool, and performed anthropometrical measurements and physical function tests. Cognitive function was assessed using a validated version of the 6CIT. Biochemical indicators assessed included serum albumin; haemoglobin, ferritin, vitamin B12, RBC folate, cholesterol and vitamin C. The MNA was used as the gold standard against which a novel screening tool was developed, using a 6-step systematic approach, namely: correspondence analysis; identification of key questions; determination of internalconsistency; correlational analyses with objective measures; determination of reference cut-off values for categories of nutritional risk; and determination of sensitivity and specificity.
Results: The new screening tool includes 9 separate concepts, comprising a total of 14 questions, as well as measurement of mid-upper arm circumference. The new tool score was positively associated with level of independence in either basic Activities of Daily Living (r = 0.472) or the more complex Instrumental ADL (IADL) (r = 0.233). A three-category scoring system of nutritional risk was developed and shown to significantly characterize subjects according to physical function tests, level of independence and cognitive function. The new tool has good sensitivity (87.5 %) and specificity (95 %), compared with the MNA scoring system. It has a very high negative predictive value (99.5 %) which means that the tool is unlikely to falsely classify subjects as well nourished/at risk when they are in fact malnourished.
Conclusion: A novel screening tool has been shown to have content, construct and criterion-related validity, and the individual items have been shown to have good internal consistency. Further validation of the tool in a new population of elderly Africans is warranted.
Questionnaire: Nutrition screening tool (pdf format, 66 kb) for use in elderly South Africans (Charlton, Kolbe & Nel, 2004)
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