Severe acute malnutrition and mortality in children in the community: Comparison of indicators in a multi-country pooled analysis

Abstract

Objectives This study aims to describe the mortality risk of children in the community who had severe acute malnutrition (SAM) defined by either a mid-upper arm circumference (MUAC) <115mm, a low weight-for-height Z-score (WHZ) <-3 or both criteria. Methods We pooled individual-level data from children aged 6–59 months enrolled in 3 community-based studies in the Democratic Republic of the Congo (DRC), Senegal and Nepal. We estimate the mortality hazard using Cox proportional hazard models in groups defined by either anthropometric indicator. Results In total, we had 49,001 time points provided by 15,060 children available for analysis, summing to a total of 143,512 person-months. We found an increasing death rate with a deteriorating nutritional status for all anthropometrical indicators. Children identified as SAM only by a low MUAC (<115mm) and those identified only by a low WHZ (Z-score <-3) had a similar mortality hazard which was about 4 times higher than those without an anthropometric deficit. Having both a low MUAC and a low WHZ was associated with an 8 times higher hazard of dying compared to children within the normal range. The 2 indicators identified a different set of children; the proportion of children identified by both indicators independently ranged from 7% in the DRC cohort, to 35% and 37% in the Senegal and the Nepal cohort respectively. Conclusion In the light of an increasing popularity of using MUAC as the sole indicator to identify SAM children, we show that children who have a low WHZ, but a MUAC above the cut-off would be omitted from diagnosis and treatment despite having a similar risk of death.

Potential consequences of expanded MUAC-only programs on targeting of acutely malnourished children and ready-to-use-therapeutic-food allocation: lessons from cross-sectional surveys

“…While this explains the higher proportion of young children and girls among children classified as SAM or MAM according to an absolute MUAC value, it may also indicate lower levels of nutritional impairments and lower associated risk of death in these subcategories of low MUAC SAM children. A recent analysis of mortality risks associated with anthropometric deficits further confirmed this hypothesis by showing a lower increase in the risk of death associated with MUAC< 115 mm in young children than in older children [3]. In that study, sex did not appear to have a role in the mortality risk associated with anthropometric deficits.…”

“…It has been argued that SAM children presenting with a WHZ < -3 but a MUAC> = 115 mm are relatively healthy, and that SAM children with a low MUAC have a higher risk of death [22,34]. These hypotheses are being challenged by a range of clinical studies [35,36], as well as by direct observation of mortality risks in cohorts of patients [20] and in large community cohorts [3]. It appears that the initially formulated hypothesis that SAM children with low WHZ are at lower mortality risk than low MUAC SAM children was driven by analyses affected by Simpson's paradox, comparing populations of cases not appropriately disaggregated [20].…”

“…It appears that the initially formulated hypothesis that SAM children with low WHZ are at lower mortality risk than low MUAC SAM children was driven by analyses affected by Simpson's paradox, comparing populations of cases not appropriately disaggregated [20]. The recent evidence suggests that SAM children with low WHZ and those with low MUAC have similar risk of death [3,20]. This evidence also shows that children presenting with both deficits (low MUAC and low WHZ) or with combined low WHZ and oedema display much higher risk of mortality than children with only one deficit (low WHZ or low MUAC).…”

“…Among them, nearly 17 million were severely wasted [1]. These children are at a higher risk of death than their well-nourished and healthy peers [2,3]. About half to one million deaths each year have been attributed to wasting in children under 5 in past publications [4,5].…”

“…A recent analysis of more than 1800 crosssectional surveys from 47 countries showed that only 16.5% of SAM children fulfilled both diagnostic criteria (MUAC < 115 mm and WHZ < -3) [19]. Re-analysis of past or modern datasets have also demonstrated that SAM children with low WHZ and SAM children with low MUAC have a similar risk of dying [3,20,21]. These studies also revealed that both deficits have additive effects on mortality risk: SAM children combining a low MUAC and a low WHZ, as well as those combining oedema and low WHZ, have a significantly higher risk of death.…”