Death of children with SAM diagnosed by WHZ or MUAC: Who are we missing?

What we know: Both weight-for-height z-score (WHZ) and mid-upper arm circumference (MUAC) are recommended to identify severely malnourished children for treatment. MUAC has distinct advantages for community-level screening; however several countries have gone further to instigate MUAC-only admissions for treatment.What this article adds: A recent review examined the consequences of excluding children with severe acute malnutrition (SAM) identified using WHZ from admission to treatment programmes. Analysis of individual data from 14,935 children admitted to a range of treatment programmes over 22 years and a literature review examined case fatality rates (CFR) with different indicators and caseload. Simpson’s paradox (mathematical coupling) results in reversal of significance that affects interpretation of the relative mortality rates of WHZ and MUAC. The analysis suggests that children with SAM identified by WHZ <-3Z and admitted for treatment have as high a risk of death as children in treatment with MUAC