© 1988 by Oxford University Press
research-article |
Arm Circumference as an Index of Protein-Energy Malnutrition in Six- to Eleven-Month Old Rural Tanzanian Children
Department of Family and Community Medicine, University of Arizona College of Medicine Tucson, Arizona
The use of arm circumference (AC) as an inexpensive indicator of protein-energy malnutrition (PEM) has been largely confined to children 12–59 months old. In this age range, AC has been shown to be relatively age-independent and highly correlated with traditional weight-for-age (W/A) indices. We analysed AC for these two properties in this anthropometric survey of rural Tanzanian children 6–11 months (n = 85) and 12–59 months (n =123) old. We compared W/A to NCHS 50th percentile standards and AC to Wolanski standards. AC cut-offs tested included a 13.5-cm mark for both age groups and 12.5 cm for those 6–11 months. The correlation between AC and W/A was 0.8214 in the 6–11-month group and 0.6771 for the 12–59-month age range. Using a W/A standard and a 13.5-cm cut off, AC had a sensitivity of 88 per cent and specificity of 57 per cent in the 6–11-month group, and respective values of 69 and 76 per cent in the 12–59-month group. In those 6–11 months old, sensitivity fell to 79 per cent and specificity rose to 95 per cent with a 12.5-cm cut off. In Wolanski's AC data, AC increased 10 per cent from 6 to 11 months (1.7 per cent/rath) and 8 per cent from 12 to 59 months (0.17 per cent/mth). Thus, despite the greater rate of AC increase in the first year of life, the absolute increase is small enough that, for the vulnerable 6–11-month age group in this region of Tanzania, a 12.5-cm cut off identifies PEM with high specificity and appropriate sensitivity to promote early intervention at the village level.