Arm circumference for age, Arm circumference and weight-for-height Z-score for the evaluation of severe acute malnutrition: a retrospective cohort study in eastern Democratic Republic of Congo

Abstract

Abstract Background Little is known about the use of mid-upper arm circumference for age (MUACZ) for diagnose of severe acute malnutrition (SAM) and its correlation with WHZ (weight-for-height Z-score) in an area endemic for severe acute malnutrition (SAM) and with a high prevalence of kwashiorkor. Our study aims to analyze the concordance between the diagnostic criteria of SAM in a region presenting these characteristics. Methods We analyzed a database of children admitted from 1987 to 2008 for the management of SAM in Eastern Democratic Republic of Congo. Anthropometric indicators (z-score) were calculated and classified into 3 categories according to WHO standards. Cohen's kappa coefficient (κ) was calculated to assess the concordance between these indicators. Results Out of the 9969 selected children aged 6 to 59 months, 30.2% had nutritional edema, 70.1% had a height-for-age (HAZ) z-score <-2, 11.5% WHZ<-3 z-score, 14.9% had a MUAC < 115 and 21.8% had a MUACZ <-3 z-score. With the classic combination WHZ and MUAC, 36% of children with SAM had both criteria at the same time and MUAC alone being the indicator that recruited more children with SAM (77%) compared with 65% with WHZ only. By replacing MUAC with MUACZ, 34% of SAM children fulfilled both criteria, WHZ and MUACZ. MUACZ alone recruited more children with SAM (88%) compared with 46% with WHZ alone. Considering these three indicators together, MUAZ remained the indicator that recruited more children with SAM (85%). WHZ and MUAC showed a moderate agreement [ κ (95% CI) = 0.408 (0.392–0.424)], WHZ and MUACZ a weak agreement [ κ (95% CI) = 0.363(0.347–0.379)] and MUAC and MUACZ a good agreement [ κ (95% CI) = 0.604 (0.590–0.618)]. Conclusion Adjusting MUAC for age increases its ability to recruit children suffering from MAS in our region. Despite this, MUAC remains complementary to WHZ because of their weak concordance.