A consultation of operational agencies and academic specialists on MUAC and WHZ as indicators of SAM
Summary of meeting report1
The treatment of severe acute malnutrition (SAM) is a costeffective, evidence-based ‘direct’ nutrition intervention, according to the 2008 Lancet Nutrition Series. Recent years have seen a significant scale-up of community-based management of acute malnutrition (CMAM) to treat children with SAM. Mid upper arm circumference (MUAC) is increasingly recommended to field staff as the indicator of choice for screening and admission to CMAM programming. However, uncertainty exists amongst many practitioners concerning the strength of the evidence to support MUAC only admissions and in particular, the consequences of non-admission for children who do not fulfil the MUAC criterion but do meet weight-for-height zscore (WHZ) cut-offs for SAM. This is complicated by observations that the two indicators do not always identify the same children and when they do, the proportions identified using both methods vary between regions and countries.
A consultation on the role of MUAC and WHZ was recently instigated by Save the Children UK (SCUK) and facilitated by the Emergency Nutrition Network (ENN) largely in order to address confusion amongst practitioners. ACF and UNHCR provided technical inputs and together with SCUK, funded the consultation.
The aim of the consultation was to identify common challenges, wider experiences and additional evidence regarding MUAC and WHZ use in the context of CMAM interventions, and to reach a shared understanding of the operational issues, existing and upcoming evidence and implications for programming.
This article summarises the final stage outcomes of the four-month consultation process, which involved 19 academic specialists and 10 operational organisations. The consultation sought to complement and inform the WHO Nutrition Guideline Advisory Group (NUGAG) process that was instigated in February 20122.
Objectives
The objectives of the consultation were:
- To present and develop SCUK’s and other operational
agencies’ understanding of the evidence on the utility
of MUAC and WHZ in the context of treatment of
SAM children 6-59 months of age in terms of:
- screening/referral, diagnosis/admission and coverage estimation
- monitoring SAM treatment progress in the individual child
- determining discharge
- To improve understanding of the challenges of implementation faced by practitioners in order to inform guidance
- To highlight knowledge/guidance gaps
- To propose pragmatic ‘stop-gap’ recommendations for practice where there is a gap in current guidance but a demand for direction from programming staff
- To consider practical application of recommendations
An original objective of the consultation included exploring the utility of MUAC and WHZ in the context of surveillance and prevalence estimation. However, this was subsequently considered to be beyond the scope of the current consultation (meriting a separate meeting). It was therefore dropped from discussions at the December meeting (see below) and no conclusions or recommendations are presented in this regard.
A premise for the consultation was that MUAC and WHZ are two imperfect indicators used as a proxy to assess nutritional status; there is no ‘gold standard’ anthropometric indicator.
Process
A discussion paper was produced by SCUK with support from the ENN and informed by discussions with Action Contre la Faim (ACF) and the United Nations High Commissioner for Refugees (UNHCR). The paper was shared with practitioners (operational agencies and individuals) in the first instance, revised to incorporate their feedback and then shared with academic specialists for input. A third version of the paper was then produced that incorporated academic specialist inputs. This informed a small meeting (31 participants, including ENN) held on the 5-6th of December 2012 to finalise the process.
Recommendations for practice
Recommendation 1:
At community level, there should be active case finding using MUAC to identify children requiring management of SAM
At health facility level (fixed or mobile), there should be systematic case finding using MUAC to identify children requiring management of SAM. If a child is not identified by MUAC, WHZ should be measured where it is feasible (capacity in terms of materials, time and trained human resources) without jeopardizing other essential health services; WHZ should be measured in particular where there are relevant clinical conditions, visible severe wasting, maternal concern and/or contextual factors (e.g. acute or prolonged emergency where more older children are affected).
Recommendation 2:
A threshold of MUAC<115mm for admission to SAM treatment applies to all children 6 months and above in all contexts.
Where WHZ is used, a threshold of WHZ <-3 for admission to SAM treatment applies to all children 6 months and above in all contexts.
Recommendation 3:
Weight gain should be used to monitor response to treatment for all children.
MUAC should be recorded in millimetres at each visit in operational research settings to establish whether MUAC monitoring can be conducted accurately and whether it is feasible for use in monitoring progress of children.
Recommendation 4:
There is no firm recommendation that can be made currently for discharge criteria, until there is more evidence from various contexts.*
Recommendation 5:
Children admitted under WHZ criterion should continue to be discharged when WHZ =-2 and free from oedema for 2 weeks, pending further research.
Recommendation 6:
The percentage weight gain should no longer be used as a discharge criterion.
*Current practices include discharge at MUAC >115mm when clinically well and no oedema and where there is follow up (such as to a SFP) or discharge at MUAC >125mm (NUGAG recommendation). Evidence is currently being collected to inform a recommendation on appropriate MUAC discharge criteria.
Key findings on factors influencing technical opinions
It became clearer through the consultation that challenges to building a consensus of opinion around the use of indicators appeared to stem from the overall weakness of the evidence base, as well as issues relating to the diversity of contexts and situations within which programming takes place and the variety of actors involved. Of note:
- There is a dearth of published evidence on this topic and what is widely available does not answer all the questions while only providing partial answers to some of them. (The NUGAG guidance (2013) acknowledges the weak evidence base on which to base recommendations regarding MUAC and WHZ use).
- Different understanding of CMAM and how it can feasibly be carried out in any given context has a strong effect on how some of the issues are viewed, the choice of anthropometric indicator and programme strategy. For example, some consider CMAM to be a treatment for the acutely malnourished most at risk of mortality; for others CMAM is for the acutely malnourished that have any excess risk of mortality.
- Contextual features and differences add to the challenge of setting global recommendations, and in applying evidence generated in one situation to another. There is great variation in caseload profile (e.g. in terms of age and sex of those children enrolled in or eligible for CMAM programmes), as well as in the available resources and capacity to deliver programmes.
The question that was most consistently raised during the consultation was whether the evidence exists to support the exclusion of children with WHZ<-3 and MUAC=115 from treatment.
Conclusions from the consultation
There was consensus at the December meeting on three major points:
- The primary objective of SAM management programmes is to identify and treat severely acutely malnourished children aged 6-59 months most at risk of short-term mortality
- MUAC and WHZ identify different children at risk of death from SAM
- On balance, MUAC appears to be the better predictor of mortality and has practical advantages. However the limitations and interpretation of the evidence base regarding this remain an area of considerable discussion.
Neither MUAC nor WHZ reveal themselves to be ideal predictors of mortality; however, of the two indicators, MUAC appears to show consistently better predictive power. Therefore, MUAC is the best anthropometric predictor of mortality currently available. The superior utility of MUAC over WHZ for community-based screening in most contexts was agreed.
The use of both WFH and MUAC together does not appear to increase the predictive power over MUAC alone3.
An important outstanding question is whether treatment of SAM addresses the mortality risk observed and related to this, what are the responses and outcomes of children identified by different anthropometric criteria (MUAC or WHZ or both) treated for SAM.
Based on the best evidence currently available alongside practical considerations, it was agreed that the programmatic approach should prioritise MUAC in screening and admission. WHZ should be used as an additional admission criterion where feasible and where doing so does not compromise the coverage of children meeting the MUAC criterion. Six recommendations for practice were made (see Box 1), with 16 associated research priorities identified that would support improvement of future recommendations.
There remain a great number of limitations in the use of the existing evidence to answer the question "What is the most relevant strategy to identify the children most at risk and who will benefit from the treatment of acute malnutrition?"
The way forward
Actions identified at the meeting with some subsequent steps taken include:
Inform the WHO NUGAG recommendations. WHO participated in the consultation process and have been updated on the meeting and recommendations to inform the NUGAG recommendations, research needs, and an upcoming WHO manual on applying the NUGAG recommendations.
Encourage the continued conversation between operational agencies and academic specialists, including the development of potential research oppor- tunities and collaborations. An en-net forum was set up in Jan 2013 for those meeting attendees and others who wish to explore opportunities for research collaboration.
Agencies attending the meeting to develop their own internal guidance. SCUK and ACF have begun drafting internal guidance and this will be shared in due course on en-net.
Interest was expressed in a follow up face-to-face meeting in the future, ideally ‘piggy backed’ onto another meeting or integrated as a topic in a technical meeting. The ENN is pursuing the idea of setting up an inter-agency technical meeting and will advocate for a follow up discussion on indicators of SAM at this meeting
The full report of the consultation is available at www.ennonline.net Feedback is welcome on en-net, under ‘Assessment’ theme.
For more information, contact: Marie McGrath, marie@ennonline.net
1Mid Upper Arm Circumference and Weight -for-Height Z-score as indicators of severe acute malnutrition: a consultation of operational agencies and academic specialists to understand the evidence, identify knowledge gaps and to inform operational guidance. ENN, SCUK, ACF, UNHCR, 2012.
2http://www.who.int/nutrition/events/2012_NUGAG_meeting1to3Feb2012_Geneva/en/index.html
3(2012). MUAC and weight-for-height in identifying high risk children. Field Exchange, Issue No 42, January 2012. p17. http://fex.ennonline.net/42/weight
Imported from FEX website