F. KOW ET AL.

Are International Anthropometric Standards Appropriate for Developing Countries? by Felicia Kow,* PhD, Catherine Geissler,** PhD, and Eliathamby Balasubramaniam,*** PhD * Department of Chemical Technology, Papua New Guinea University of Technology **Department of Food and Nutrition Sciences, King's College, The University of London ***Department of Applied Physics, Papua New Guinea University of Technology

Introduction In 1978 the World Health Organization has endorsed' the NCHS (National Centre for Health Statistics) growth curves2 as the anthropometric standard for international use in Maternal and Child Health Care. Other international standards such as the Harvard (Boston) standard 3 have long been adopted by developing countries such as Papua New Guinea* as the reference standard. Yet using such an international standard as yardstick, with a standard cut-off point of 80 per cent weight-for-age standard, malnutrition has been rated as 38 per cent of children under 5 years on average, and as high as 60 per cent in some areas 5 of Papua New Guinea. There has been much controversy 6 " 13 regarding the validity of the use of such international standards based on well-nourished children of Caucasian origin growing in a good environment in developed countries. Yet the establishment of national standards is both extensive and expensive. In addition, more than

Acknowledgements Supported by Papua New Guinea University of Technology, Papua New Guinea Biology Foundation, and South Patific Commission. We are grateful to Dr J. Shields of Papua New Guinea Medical Research Institute for her assistance in Parasitology, and medical personnel and testers from the University of Papua New Guinea for their involvement in the Survey. Correspondence: F. Kow, School of Fisheries, Australian Maritime College, P.O. Box 21, Beaconsfield, Tasmania 7251 Australia. Journal of Tropical Pediatrics

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one set of standards would be required when there are many ethnic groups present in a country. This paper attempts to investigate the validity of using international standards as reference standards for developing countries such as Papua New Guinea by comparing anthropometric classifications based on various percentages of standard against functional indicators of malnutrition. Anthropometric measures in themselves do not necessarily indicate malfunction. An individual may be small and thin and yet apparently healthy in which case the term 'malnourished' may be misplaced if quality of life is not impaired. Objective measures can include present morbidity. The interaction between nutrition and infection is well documented. It has been shown that, in tropical countries in particular, many infections occur more easily, persist longer, and have a much higher mortality rate in malnourished children; while infectious diseases also play an important role in the initiation of malnutrition itself. Many infections are characterized by poor appetite, vomiting, and diarrhoea. The heavy infestation with various intestinal parasites and the continual exposure to malarial parasites during early childhood have direct influence on mutrition, since the parasites too have their needs for various nutrients which are derived from the host child. One of the salient features of malaria parasite infection is splenomegaly due to the increase in reticuloendothelial cells. Diarrhoea, intestinal parasitic load, and splenomegaly and signs suggesting protein-energy malnutrition, could therefore be used as indicators of functional impairment against which to compare anthropometric indicators as is done in this paper. i Oxford University Press 1991

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Summary To test the validity of using international standards as references for the assessment of nutritional status, investigations have been carried out on pre-school aged children selected from three distinct ecological environments in Papua New Guinea. Field work included anthropometric measurements (weight, height, triceps skin-fold, mid-upper-arm circumference, mid-upper-ann muscle circumference), together with pathological and clinical assessments (intestinal helminths, diarrhoea, splenomegaly, PEM signs). The findings indicate that any deviation below standard weight, height, and arm circumference is associated with greater prevalence of disease. International standards are therefore appropriate for preschool aged children in Papua New Guinea and by inference in other developing countries.

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1. Body weight: a portable-platform beam balance (MPS 110 Field Survey Scales, Camden Weighing Ltd. London, UK) was used, to weigh children with minimum clothing, to nearest 0.1 kg. Younger infants were carried by adults and the difference obtained. 2. Height or length: a Nivotoise (Stanley, Paris, France) height-measuring instrument was used to measure the subject standing upright, to the nearest 1 mm. For children under 1 m in height a measuring length-board (Civil Engineering Services, University of Technology, Lae, Papua New Guinea) was employed. 3. Mid-upper-arm circumference (MUAC): a micromatic (Stanley, Paris, France)flatflexibletape, read to the nearest 1 mm, was used to measure the 38

MUAC at midpoint between the acromial and olecranon processes without compressing the skin of the arm which was hanging loosely. 4. Triceps skin-fold thickness: the triceps skin-fold parallel to the long axis of the arm was picked up 1 cm above the site located for MUAC and the thickness at the site was measured with Harpenden HfTfW calipers (Holtain Ltd. Crymych UK) to the nearest 0.1 mm. 5. Mid-upper-arm muscle circumference (MUAMC): this is calculated from MUAC and skin-fold thickness measurements.14 6. Intestinal helminths: a stool specimen was obtained from each child and stored in a portable gas fridge before analysis. The Gordon and Whitlock technique'5 was adopted for counting the number of ova or larvae. Correction factors16 were applied to correct for stool consistency (i.e. weight of sample incremented to compensate for the softness of the stool): fully formed x 1; mushy formed x 1.5; mushy x 2; mushy diarrhoetic x 3; frankly diarrhoetic x 4; watery x 5. 7. Clinical assessments: an examination was made for signs suggesting protein-energy malnutrition (PEM). The signs considered were oedema, moon face, muscle wasting, hepatomegaly, flaky-paint dermatosis, psychomotor change and dyspigmented, and easily pluckable, thin, sparse hair. Evidence of splenomegaly was also sought and information obtained if the child had diarrhoea during the week of the survey or the previous one. Diarrhoea was understood by the mothers to be a condition in which bowel movements were frequent and fluid. All testers were trained before the survey and clinical and pathological assessments were carried out by medical personnel and a parasitologist. Anthropometric standards for weight and height/ length are those taken from the NCHS (National Centre for Health Statistics) growth curves.2 For MUAC the standard from Jelliffes' monograph1* is adopted, and for triceps skin-fold thickness, the Tanner and Whitehouse standard17 is used. The data are analysed and presented by (a) a graphic method and (b) chi-square test. The graphic method

The anthropometric measurements from each child were compared with the standard values and expressed as percentage of standard. Children of the same anthropometric standards were then grouped together for every 5 per cent intervals of the standards (e.g. 96-100 per cent, 101-105 per cent). The proportion of the healthy children (those with no infestation of intestinal helminths, presence of diarrhoea, PEM signs nor splenomegaly) in the group was calculated. A Journal of Tropical Pediatrics

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Methods Pre-school aged children (under 7 years), 799 in total, have been selected from three distinct ecological environments: Lae (urban, 290), Wasu (rural coastal, 233), and Aseki (rural upland, 276) in the Morobe Province of Papua New Guinea. The racial component of the urban population is mixed while that of the rural areas is homogeneous. People from the two rural areas differ in racial origin, spoken language, and culture. A random sampling method was originally attempted. However, because this method required the selection of households, the level of response indicated that it would not be suitable for later use. Hence, random sampling method was discarded. The method chosen was for the community leaders to encourage the attendance at individual villages or settlements, of as many mothers as possible, and this formed the basis of the sample. Each study area was divided into sections in line with the census division (in Papua New Guinea the whole country is divided into different census divisions) and each section was sampled and surveyed accordingly. The response was estimated to be above 70 per cent. The anthropometric measurements taken for each child included weight, height, mid-upper-arm circumference, and skin-fold thickness. Included were also recordings of various forms of morbidity. Similar health parameters have been chosen for the three study areas as far as possible. However, where the prevelance was less than 1 per cent or none that parameter has not been employed since statistical analysis would invalidate the use of such parameter. Hence, in the upland study area of Aseki where malarial mosquito cannot normally survive and the prevalance of splenomegaly was nil, splenomegaly as a health parameter in Aseki has been excluded. Similarly, less than 1 per cent of children showed signs of PEM in Lae and Wasu, and evidence of diarrhoea in Wasu and these results have been excluded. The measurements performed are listed as follows:

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FIG. I. The percentages of healthy children (without intestinal helminths, O; diarrhoea, A; splenomegaly, El), from the Lae study area when related to different levels of the anthropometric standards. graph was then plotted showing for each percentage range of anthropometric standard the percentage of children who did not manifest each of the health variable separately (i.e. the healthy sample in terms of each health variable). Chi-square test The anthropometric measurements from each child were compared with the standard values and expressed as the percentage of the standard. These calculated percentage values were used for the chi-square test. The relationships between anthropometric variables and health variables were investigated using chisquare test based on 2 by 2 contingency tables. For each anthropometric variable, i.e. percentage of the international standard, a series of tests was run to determine the level which would have the maximum chi-square value when relating it to the particular health variable. This maximum value not only gives an indication of the strength of the relationship between Journal of Tropical Pediatrics

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the two variables, but it also indicates what percentage of the standard could be used as practical cut-off values below which malnutrition, as evidenced by health disorders, could probably be assumed. It should be included here that the use of maximum chi-square statistis for determination of cut-off points has been used by many workers such as Miller and Sigmund, 18 and Halpern. 19 Results

The graphic method The results for the graphic method are presented in Figs 1-3 for weight, height/length, MUAC, MUAMC, and triceps skin-fold thickness standards for the three study areas. The results from Lae study area (Fig. 1) show that the clearest relationship between health as defined by lack of helminths, or diarrhoea or splenomegaly is with height. The higher the percentage standard up to 39

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FIG. 2. The percentages of healthy children (without intestinal helminths, O; splenomegaly, • ), from the Wasu study area when related to different levels of anthropometric standards. 100 per cent, the higher the percentage of population is healthy. The poorest relationship is with skin-fold where there is no discrimination between the percentage healthy and the percentage standard skin-fold below approximately 90 per cent. Above this level the proportion healthy increases dramatically for all three health variables, but particularity in relation to helthminths. The reversal of trends at the extremes of sample could be ascribed to that this being artefacts probably due to small number of subjects involved. However, this reversal of trends are not observed in the other two study areas though the subject number involved is also relatively small at the extremes. For the other two study areas the relationship curves (Figs 2 and 3) are less smooth though the relative numbers in each cell are similar to those in the Lae area. However, the trends are similar to those found in Lae (Fig. 1). For all three study areas splenomegaly and helminths as health variables appear to be more closely related to anthropometric indicators than diarrhoea 40

and PEM signs. In addition, in all areas the percentage with helminths increases as percent skin-fold measurement increases up to 80-90 per cent standard and then the relationship is reversed. This may indicate that when a child is very thin and malnourished the helminths also become malnourished and die. Further work is necessary to investigate this. Chi-square test The maximum chi-square technique is illustrated in Table 1 where the relationship between the weight-forage standard and incidence of diarrhoea in Lae children is investigated. The chi-square value and the corresponding significance level are determined for each level of the weight-for-age standard ranging from 80 to 105 per cent at 5 per cent intervals. The maximum chi-square value is 16.5 for 85 per cent of the standard with a probability level of

Are international anthropometric standards appropriate for developing countries?

To test the validity of using international standards as references for the assessment of nutritional status, investigations have been carried out on ...
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