Review of “non-response” to wasting treatment

The World Health Organization 2023 guidelines define recovery in children aged 6-59 months with severe wasting and/or nutritional oedema as reaching a weight-for-height z-score (WHZ) ≥-2 and mid-upper arm circumference (MUAC) ≥125mm, with no nutritional oedema, for two consecutive weeks. Children failing to meet these criteria within 12-16 weeks are classified as ‘non-responders’ (NR) and considered treatment failures. This study hypothesises that non-responders are not a homogeneous group and may exhibit different growth trajectories.

Drawing data from 14 studies, the study analysed children receiving treatment for wasting, excluding those with oedema or implausible anthropometric measurements. The analysis compared recovered children to non-responders and further categorised non-responders into ‘low growth NR’ and ‘high growth NR’, distinguishing between those who showed minimal growth and those who responded to treatment but did not recover within the maximum treatment duration. Growth trajectories and predictors of each group were explored, involving nearly 16,000 children.

Findings revealed that non-responders were generally younger, had a higher proportion of severe wasting, and displayed worse anthropometric indices at admission than recovered children. The high growth NR group started with poorer anthropometric status but exhibited growth along a near-parallel trajectory to the recovered group. The low growth NR group showed limited growth and higher morbidity. 

The study underscores the need to differentiate between high growth NRs, who are responding well but require longer treatment, and low growth NRs, who show little to no improvement. Classifying high growth NRs as treatment failures risks premature discharge and underestimation of therapeutic feeding programme effectiveness. For instance, children admitted with very low MUAC (~110mm) may take over four months to recover. Conversely, low growth NRs likely have underlying health conditions constraining their growth, necessitating closer medical investigation.

The findings emphasise the importance of weekly MUAC and weight monitoring to assess individual growth trajectories. Operational research is needed to determine whether individualised growth monitoring is feasible or if a standardised approach should be adopted, such as extending treatment duration for children with MUAC <110mm or weight-for-age z-score <-3 at admission. While prolonged treatment incurs additional costs, it is likely cost-effective in reducing vulnerability to severe illness and mortality. Given that previously wasted children face a 3-5 times higher risk of relapse or death within six months post-discharge, keeping high growth NRs in treatment longer could improve long-term outcomes.
For low growth NRs, existing community management of acute malnutrition guidelines remain relevant, but early referral for further investigation should be considered if no improvement in weight or MUAC is observed by weeks 3 to 4. The study calls for a reconsideration of the “non-responder” label, advocating for a more nuanced approach to treatment categorisation that acknowledges differences in recovery potential.