Background and rationale {6a}
The field of nutrition divides undernutrition into two categories: micronutrient deficiencies and growth deficits. Micronutrient deficiencies arise when specific type 1 micronutrients, such as iron, are lacking in the diet [
1]. These deficits give rise to a specific symptom, anemia in the case of iron, that is rather easy to identify [
2] and treat via supplementation [
3,
4]. Type 1 micronutrients include all vitamins as well as some minerals such as iodine, copper, and calcium [
1]. Growth deficits occur when either type 2 micronutrients or macronutrients are lacking in the diet leading to slowed height and weight gain. Type 2 micronutrients include zinc, potassium, and magnesium [
1].
Growth deficits are further divided into the overlapping subcategories of wasting, stunting, and underweight [
5]. Being wasted is strictly defined as a weight-for-height
z-score (WHZ) below −2, stunted as a height-for-age
z-score (HAZ) below −2, and underweight as a weight-for-age
z-score (WAZ) below −2 [
6]. Both being stunted and wasted overlap heavily with the category of children who are underweight [
5]. Up to 93% of underweight children are also stunted or wasted and 17% accumulate a degree of both deficits [
5].
All growth deficits are associated with an increased risk of mortality compared to children with no growth deficits. Moderately (
z-score between −2 and −3) stunted, underweight, and wasted children have a 2.3-, 2.6-, and 3.4-fold increased risk of mortality, respectively [
7]. Severe (
z-score below −3) stunting, underweight, and wasting are associated with 5.5, 11.6, and 9.4 increased risk of mortality, respectively [
7]. Accumulating several deficits increases substantially the mortality risk: children with both stunting and wasting, either moderate or severe, have a 12.3-fold increase in their risk of mortality [
8].
Currently, only severe wasting is intentionally addressed via therapeutic feeding [
9‐
11]. Children are admitted to therapeutic feeding programs for severe acute malnutrition (SAM) if their WHZ is below −3, they have a mid-upper arm circumference (MUAC) below 115 mm or in the presence of edema [
12]. MUAC is used to detect being wasted as it reflects muscle mass deficits [
13,
14], predicts mortality [
15], is quick and easy to measure, and thus is used in community screening campaigns to identify malnourished children [
9].
However, it is unclear whether the use of WHZ <−3 and MUAC <115 mm is optimal for capturing all children at the highest risk of mortality and for targeting all that would benefit from nutritional supplementation. An analysis of community-based cohort data from Senegal found that up to 62% of children at risk of death associated with growth deficits were missed when using WHZ <−3 and MUAC <115 mm [
16].
Nutritional treatment is currently prescribed based on the weight of the severely wasted child and aims to fulfill 100% of the daily nutrient needs of the recovering child [
10,
11]. However, recent evidence has shown that it is possible to reduce the dose of ready-to-use therapeutic food (RUTF) prescribed without undermining the recovery of treated children [
17,
18] all the while making treatment less costly per child [
19].
Beyond reducing the RUTF dose prescribed, simplifying the dosing regimen to 1 or 2 daily sachets per child based on the MUAC category instead of weight has been proposed and tested with encouraging results [
17,
18]. The advantage of such a simplified dosage is both its simplicity to health agents prescribing treatment as well as to caregivers administering the treatment to children at home.
The simplified dosing regimen is only one aspect of a broader current initiative to towards simplifying malnutrition treatment [
20]. Despite some improvements in treatment coverage over the past decade, still an estimated 70% of children with SAM and even more with moderate acute malnutrition (MAM) are left untreated in the community [
21]. This is mostly attributed to the inexistence of screening and treatment services [
22] which are often seen as burdensome and complex to run [
23]. Simplified approaches to the detection and treatment of malnutrition have been proposed as a solution to scale up treatment services and enhance continuity of care [
24].
One commonly proposed simplification is the combination of treatment of moderately and severely wasted children under the same program to ensure a continuity of care for wasted children and also prevent deterioration into more severe forms. Currently, children with MAM are eligible for supplementary feeding which can be in the form of a nutritional supplement providing 500 kcal/day [
22]. However, treatment is oftentimes not available [
22]. Recent recommendations on MAM treatment have also created some confusion about whether MAM should always be treated [
25] despite evidence that moderately wasted children benefit from supplementation [
26].
Moreover, there is growing interest in breaking the separation between stunting and wasting [
27] and thus expanding the focus from treatment to include secondary prevention of severe malnutrition [
28]. Traditionally, stunting has been largely seen as a non-treatable condition and is typically addressed through preventive interventions [
29]. However, evidence is emerging that previous wasting episodes may be driving the development of stunting [
30] and that stunting pre-disposes to wasting [
31]. Both conditions seem to share some common risk factors and potential mechanisms driving the increased risk of mortality [
27]. Particularly in contexts where both stunting and wasting are prevalent, addressing both seems critical to sustainably decrease the associated mortality risk.
Another simplification is the use of only MUAC and edema to admit children to treatment [
32‐
36]. This enables leaving out the more time-consuming and error-prone procedures of weight and height measurements and the complex interpretation of WHZ tables. Admitting children with a MUAC <125 mm or edema to malnutrition treatment programs has been proposed as a means to facilitate decentralization of treatment to the less trained community health worker force [
32,
34,
35].
However, using only MUAC <125mm and edema still leaves out children who are at risk of mortality associated with other growth deficits [
16]. In a Senegalese cohort study that followed children in time, 34% of deaths among children with some growth deficit were not detected with a MUAC <125 mm [
16]. On the other hand, all of these would have been captured with the use of WAZ <−2.8 [
16]. This finding has led to the suggestion that WAZ <−3 could be added as an independent admissions criterion for therapeutic feeding programs in addition to MUAC <125 mm. This would enable capturing all wasted, stunted, and underweight children with an increased risk of mortality due to their growth deficits.
Currently, there is little evidence to inform the debate about whether children with MUAC ≥125 mm and WAZ <−3 respond to treatment and, if so, what treatment protocol should be used. There are numerous studies identifying optimal treatment protocols for children with MUAC <125 mm [
32,
34,
35]. These protocols reduce the RUTF dose progressively towards the end of the treatment. Clinical trials have demonstrated that these alternative dosing protocols are non-inferior to the standard dosing regimen that keeps a “full” RUTF dose until the end of treatment [
33,
34,
37]. However, to our knowledge, there is no data about optimal therapeutic feeding protocols for children with MUAC ≥125 mm and WAZ <−3. Currently, children with WAZ <−3 but MUAC ≥125 mm do not receive any treatment in areas implementing simplified protocols with MUAC-only-based admissions.
This study will assess whether children with WAZ <−3 but MUAC ≥125 mm benefit from therapeutic feeding and whether a simplified protocol is at least as effective as the more complicated weight-based standard protocol for this population. The publication of this study protocol aims to improve transparency and share information to support the development of similar studies that seek to study the optimization of the diagnostic criteria for malnutrition treatment and the therapeutic dosing of RUTF.