Mid-arm circumference for detecting malnutrition during infancy.

Mid-arm circumference (MAC) has been extensively used at 1-5 years of age as an age-independent indicator of protein-energy malnutrition (PEM). Its role below 12 months of age has not been studied adequately and a search for a clinically reliable cut-off point has not been systematically done. This study was planned to establish the age-independent character of MAC within the 6-12 month age group and identify a cut-off point demonstrating the maximum sensitivity and specificity in detection of PEM. Two hundred and forty malnourished infants [< 80% weight for age (W/A) of 50th percentile of NCHS standard] were included with even distribution into 6 subgroups; 240 healthy infants were taken as controls. MAC within the age of 6-12 months was found to be age independent with an overall increase of 5.1%. By using various cut-off points a value of < or = 12.5 cm of MAC proved to be having maximum sensitivity (92.1%) and specificity (88.3%). MAC is, therefore, a simple, age independent, informative measurement for early assessment of PEM by using single cut-off point < or = 12.5 cm, and can serve as a screening test for targeting infants for meaningful utilization of nutritional programmes. Since nearly all MAC tapes in current use already have < or = 12.5 cm colour coded cut-off, no new tapes are necessary.