Diagnostic ability of mid-upper arm circumference-to-length ratio in detecting wasting among infants aged 1-6 months in Ethiopia

Abstract

Mid-upper arm circumference (MUAC) is an age-sensitive anthropometric measurement in infants. However, exact age is difficult to know, particularly in low-income countries. We evaluated the diagnostic accuracy of an age-independent mid-upper arm circumference-to-length (MUAC/L) ratio measurement in detecting wasting among infants aged 1-6 months in Ethiopia. A facility-based diagnostic accuracy study was conducted on 467 in-patient infants aged 1-6 months from March to May 2019. The receiver operating characteristic (ROC) curve was used to evaluate the ability of MUAC/L to detect wasting. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and positive and negative predictive values were calculated. The magnitude of severe wasting was 216 % and moderate wasting was 130 %. The area under the ROC curve (AUC) of MUAC/L was 077 (95 % CI 073, 081) for detecting moderate wasting and 092 (95 % CI 089, 094) for detecting severe wasting. MUAC/L had a sensitivity of 911 % (95 % CI 813, 944), a specificity of 847 % (95 % CI 806, 882), a positive likelihood ratio of 582 (95 % CI 453, 748) and a negative likelihood ratio of 013 (95 % CI 007, 022) in total infants. The optimal MUAC/L cut-off was <0190 for boys and <0185 for girls. MUAC/L had an AUC of 077 and 092 in predicting moderate and severe wasting in infants aged 1-6 months, respectively. Using MUAC/L to treat Ethiopian infants with severe wasting and infants with similar characteristics in other countries could improve treatment coverage.