Peer-reviewed article

Analysing concordance between MUAC, MUACZ, and WHZ in diagnosing acute malnutrition among children under five in Somalia.

Sydney Garretson, Shelley Walton, Kemish Kenneth Alier, Samantha Grounds, Qundeel Khattak et al. · 12 Dec 2025

Summary

Written by AI, not yet AICS's view · claude-haiku-4-5-20251001

This study compared three methods of diagnosing acute malnutrition (wasting) in Somali children under five: MUAC (mid-upper arm circumference), MUACZ (age-adjusted MUAC), and WHZ (weight-for-height z-score). MUAC alone detected only 6% of children identified as wasted by WHZ, while MUACZ showed better agreement. The researchers identified age-specific measurement thresholds that could improve detection of wasted children and guide treatment programmes in resource-limited settings.

Key points

MUAC alone failed to identify 94% of WHZ-wasted children, detecting wasting in only 1.5% of the sample versus 14.8% by WHZ
MUACZ showed fair concordance with WHZ (κ = 0.385), compared to slight concordance for MUAC alone (κ = 0.089)
Age-specific MUAC thresholds were identified: 13.7cm for ages 9-23 months and 14.4cm for ages 24-59 months, both accurately diagnosing >76% of wasted children
MUAC, age, sex, and stunting were all statistically significant variables for predicting child WHZ in regression modelling
The study recommends policymakers review wasting measurement guidelines and examine how adapted screening thresholds would affect health facilities and treatment availability

Limitations

This is a secondary analysis of trial data from two high-wasting regions of Somalia, so findings may not generalise to lower-wasting areas or other contexts. The study does not present long-term outcomes or mortality data to validate whether use of revised thresholds actually improves child health outcomes.

Abstract

BACKGROUND: Acute malnutrition, also known as wasting, affected an estimated 45 million children under five (CU5) globally in 2023. Wasting is measured using a child's mid upper arm circumference (MUAC), weight-for-height z-score (WHZ), or nutritional oedema. In low-resource contexts, MUAC is often the only measurement used to regularly screen for malnutrition, but recent research suggests MUAC alone fails to diagnose 25-80% of WHZ-wasted children. Mid upper arm circumference, an age-adjusted MUAC z-score, may identify additional cases missed by MUAC alone. METHODS: This was a secondary analysis of 1408 CU5 enrolled in a cluster-randomised controlled trial in two high-wasting regions of Somalia. This analysis explored wasting prevalences, concordance between indicator pairs, linear regression modelling, and receiver operating characteristic (ROC) analysis using WHZ as a reference standard to examine alternative MUAC and MUACZ thresholds. RESULTS: Wasting prevalence was 1.5% by MUAC, 8.5% by MUACZ, and 14.8% by WHZ. Mid upper arm circumference alone failed to identify 94% of WHZ-wasted children. There was slight concordance between MUAC and WHZ (kappa (κ) = 0.089) and fair concordance between MUACZ and WHZ (κ = 0.385). Linear regression indicated that MUAC, age, sex, and stunting were all statistically significant variables for estimating child WHZ. Using WHZ as a reference standard, a MUAC of 13.7cm and MUACZ of -0.9 both accurately diagnosed >82% of wasted children ages 9-23 months. A MUAC of 14.4 cm and MUACZ of -1 both accurately diagnosed >76% of wasted children ages 24-59 months. CONCLUSIONS: Poor concordance between MUAC and WHZ should prompt review of wasting measurement guidelines for this population. Stratified analyses and regression modelling showed increased MUAC with age among CU5. MUACZ or age-specific MUAC thresholds may identify more truly wasted children, improving coverage of treatment interventions. Policymakers should examine how adapting screening guidelines impacts health facilities and treatment availability. Future studies should consider long-term outcomes and mortality associated with increased thresholds of MUAC and MUACZ. REGISTRATION: The cluster-RCT is registered at ClinicalTrials.gov, ID: NCT06642012.

Findings the Hub has extracted

Each claim below is labelled by its type of design and links back to this report.

Survival

Problem

Acute malnutrition (wasting) affects millions of children under five globally, but current screening methods using MUAC alone miss most truly wasted children in low-resource settings

Intervention: Comparison of age-adjusted MUAC (MUACZ) and age-specific MUAC thresholds against weight-for-height z-score (WHZ) as diagnostic methods for acute malnutrition
Population: 1,408 children under five enrolled in a cluster-randomised controlled trial in two high-wasting regions of Somalia

Key finding

MUAC alone detected wasting in 1.5% of children versus 14.8% by WHZ, failing to identify 94% of WHZ-wasted children

Experimental