Reliability of the Mid Upper Arm Circumference for the Assessment of Wasting among Children Aged 12-59 Months in Urban Ibadan, Nigeria

Abstract

Although the mid upper arm circumference (MUAC) is used as a proxy to assess wasting in children, its validity abounds in controversies. This study therefore assessed the validity of MUAC as a measure of nutritional status among children aged 12-59 months in urban setting in western Nigeria. A cross sectional study of children aged 12-59 months in selected nursery schools in Moniya, Akinyele local government area, Oyo state was carried out between February to April 2010. The age, weight, length and MUAC, were obtained from the school children who were selected through total sampling. The sensitivity, specificity, positive predictive value, and negative predictive values of the MUAC were determined using weight for age as gold standard (underweight). Z-Scores for anthropometric indicators were calculated using EPI-NUT programme. Receivers operating curve was prepared to determine the optimal cut off of MUAC for the sensitivity and specificity. The overall prevalence of under nutrition among the respondents was 5.6%. The mean mid upper arm circumference was 15.47 ± 1.4 cm and appears to increase with age from 11.49 ± 3.0 at 12-23 months and peaks at age five with a value of 18.05 ± 3.5. At 13.5 cm cut off, the sensitivity of MUAC is 20%, and the specificity is 95.3%, with a Kappa of 16.7%. The receivers operating curve reveals an optimum cut off of 15.5 cm with optimal but improved MUAC sensitivity of 80% and specificity of 53.5%. Thus MUAC was a poorly sensitive indicator of under nutrition at a cut-off below 13.5 cm but highly sensitive at 15.5 cm. A higher cut off value is therefore for recommended for screening for acute malnutrition among under five children.