Optimal Screening of Children with Acute Malnutrition Requires a Change in Current WHO Guidelines as MUAC and WHZ Identify Different Patient Groups

Abstract

BackgroundTimely treatment of acute malnutrition in children <5 years of age could prevent >500,000 deaths annually. Screening at community level is essential to identify children with malnutrition. Current WHO guidelines for community screening for malnutrition recommend a Mid Upper Arm Circumference (MUAC) of <115 mm to identify severe acute malnutrition (SAM). However, it is currently unclear how MUAC relates to the other indicator used to define acute malnutrition: weight-for-height Z-score (WHZ).MethodsSecondary data from >11,000 Cambodian children, obtained by different surveys between 2010 and 2012, was used to calculate sensitivity and ROC curves for MUAC and WHZ.FindingsThe secondary analysis showed that using the current WHO cut-off of 115 mm for screening for severe acute malnutrition over 90% of children with a weight-for-height z-score (WHZ) <−3 would have been missed. Reversely, WHZ<−3 missed 80% of the children with a MUAC<115 mm.ConclusionsThe current WHO cut-off for screening for SAM should be changed upwards from the current 115 mm. In the Cambodian data-set, a cut-off of 133 mm would allow inclusion of >65% of children with a WHZ<−3. Importantly, MUAC and WHZ identified different sub-groups of children with acute malnutrition, therefore these 2 indicators should be regarded as independent from each other. We suggest a 2-step model with MUAC used a screening at community level, followed by MUAC and WHZ measured at a primary health care unit, with both indicators used independently to diagnose severe acute malnutrition. Current guidelines should be changed to reflect this, with treatment initiated when either MUAC <115 mm or WHZ<−3.

Does mid upper arm circumference identify all acute malnourished 6–59 month old children, in field and clinical settings in Nigeria?

“…The variation between WHZ and MUAC has also been reported by Laillou A et al 11 The report showed that using the WHO MUAC cut-off of 11.5 cm for screening, over 90% of children with a weight-for-height z-score (WHZ)<-3 were missed and WHZ < -3 missed 80% of the children with a MUAC of 11.5 cm. In our study, no subject with WHZ < -3 was identified by MUAC cut-off point contrary to the WHO report of similar prevalence of SAM when both MUAC and WHZ are compared.…”

“…18 There is a need to develop stand-alone parameters that can identify all malnourished children whether during screening in the field or in the clinics. Some authors 11,13 have suggested a MUAC of 13.5 cm and 15.5 cm as having a good sensitivity and specificity. Among the entire subject identified as SAM either by WHZ, BAZ or MUACZ, MUAC ranged from 11-15 cm.…”

“…[9][10][11] Weightfor-height below -3 Standard Deviation (SD) is a highly specific criterion to identify severely acutely malnourished infants and children. 10 Several authors indicate discrepancies between prevalence of malnutrition obtained using WHZ and those obtained using MUAC of < 11.5 cm for SAM and < 12.5 for moderate acute malnutrition (MAM).…”

“…Although WHO reports a similar prevalence of SAM when using both parameters, 10 a higher prevalence has been reported with WHZ parameters. 11 Thus, the utility of MUAC is brought into question when identifying children with several forms of malnutrition in a clinical setting and even in the field, given its simplistic application.…”

Mid-upper arm circumference (MUAC) performance versus weight for height in South African children (0–59 months) with acute malnutrition

“…In wasted children MUAC has often been used as a pre-screening tool, while W/H has been used to confirm the diagnosis. 6,7 Both anthropometric indices show an indirect reflection of fat and lean muscle catabolism that is obvious in SAM and are therefore the anthropometric measurements of choice in assessing the magnitude of malnutrition. 8 However, W/H requires the measuring of weight and height, as well as a reference table, while using MUAC requires only the use of a tape measure with a fixed cut off.…”