Hello.
In my view MUAC was met to be used in mass screening especially in surveys and outreaches.
However, other parameters like W/H , W/A and H/A must be used to a suspected case to draw a common conclusion.
The best time again to use MUAC is inpatient, to follow up improvement for the severely malnourished children admitted either by MUAC or weight/height.
For children below five years visiting health facilities are being screened using weight for age, height for age and weight for height to determine nutritional status.
Regards.
Namesius.

Hi Anonymous.
Please find below links to a couple of previous discussions along a similar line related to MUAC and the detection of younger children.

https://www.en-net.org/question/3412.aspx
https://www.en-net.org/question/1848.aspx

Current recommendations are that MUAC and Weight for Height (WFH) are considered independent criteria for admission. Namesius makes the point that children that are not detected by MUAC in MUAC only programmes may possibly be identified as being malnourished by WFH (and by bilateral oedema).

So, just to clarify, in a MUAC only programme there will be exclusion of children with WFH less than -3 z scores with MUAC equal or greater than 11.5cm (rather than excluding males with high risk of mortality by MUAC with MUAC <11.5cm).

The proportion of children excluded from treatment according to WFH criteria by age / sex will vary by context due to growth differences between populations. A simple way of checking this would be to look at nutrition survey data to see which children (by sex and age) with WFH < -3 would be excluded from a MUAC only programme in your area. There has been much debate on whether these exclusions are appropriate or not but I don't think that is your question.

Just to follow up on a couple of comments by Namesius for clarification.

1. MUAC was not 'intended' just as a means of 'mass screening'. MUAC was previously used only for screening but a generation of research has changed that. It was argued for a long time that it should (now recommended) be used as an INDEPENDENT admission criterion to selective feeding programmes because of its relationship to elevated mortality risk. If a child is identified with MUAC < 11.5cm there is no other measure needed to confirm the child's eligibility for admission. (and vice versa for weight for height). Two stage screening (i.e. using MUAC in the community to screen and WFH at the health facility to admit) is from a bygone age and contradicts current WHO recommendations.

2. The current recommendation is that the criterion used to admit the child to the programme is the one that should be used to discharge the child from the programme. A child admitted by MUAC should be discharged by MUAC. For daily "follow up of improvement" of the patient's condition in inpatient care, it is far more likely that weight is used along with other clinical indicators to monitor an appropriate response to treatment irrespective of the admission criterion. However, progression to other phases of inpatient treatment, or transition to the outpatient setting for continued rehabilitation is not dependent on anthropometry, either by MUAC or by weight for height.

Paul

I haven't seen any study looking specifically at that. As mentioned in another reply, it would vary by population, but I wonder if the WHO Growth Reference data could be used to show what the expected exclusion would be. Are you thinking about answering the questions yourself?

Thanks for the quick and detailed replies. All very helpful.

There seems to be increasing discussion about piloting the simplified protocol (MUAC admission only) with aim of improving programme coverage, cost-effectiveness. To give a bit more context around my question I was wondering what the potential gender and age bias of using MUAC only could be (I was wondering if there any general findings that the bias tends to very small, or if in practice it is found to be much larger and many acutely malnourished boys and older children could in theory be missed from MUAC only programmes)? i.e. does the increase in coverage gained from implementing a MUAC-only simplified protocol outweigh very small potential gender and age biases that occur when using MUAC Only? Or are the biases considered to be much more significant and as such MUAC only admission treatment programmes are not advised?

Also, what about the risk of excluding WHZ children in MUAC only programmes (I've seen the 2018 Golden & Grellety research which suggests up to 45% WHZ SAM cases could be excluded) depending on the context.

Slightly deviating from the initial question, but still related: what is the current thinking on the simplified protocol? Is it envisaged that acute malnutrition treatment programmes will move in the direction of MUAC only admissions? Or is the simplified protocol likely to remain as indicated in the MAM Decision toolkit for exceptional circumstances only until the standard protocol can be implemented?

With potential to exclude WHZ SAM children plus gender and age bias, I’m slightly nervous about MUAC only programmes. (is it correct to be cautious or in reality are the risks of exclusions really quite small and from a public health nutrition perspective, the increased coverage from MUAC admissions far outweighs any potential negative consequences of exclusions?)

To follow-up on Anonymous 24408’s post, please find below great piece of work done by Grellety and Golden.
1. Grellety E, Golden MH. (2016). Weight-for-height and mid-upper-arm circumference should be used independently to diagnose acute malnutrition: policy implications. BMC Nutrition, 2(1), 10. https://doi.org/10.1186/s40795-016-0049-7
2. Grellety E, Golden MH. (2018). Severely malnourished children with a low weight- for-height have a higher mortality than those with a low mid-upper-arm-circumference: I. Empirical data demonstrates Simpson’s paradox. Nutrition Journal, 17(1), 79. https://doi.org/10.1186/s12937-018-0384-4
3. Grellety E, Golden MH. (2018). Severely malnourished children with a low weight- for-height have similar mortality to those with a low mid-upper-arm-circumference: II. Systematic literature review and meta-analysis. Nutrition Journal, 17(1), 80. https://doi.org/10.1186/s12937-018-0383-5
4. Grellety E, Golden MH. (2018). Severely malnourished children with a low weight- for-height have a higher mortality than those with a low mid-upper-arm-circumference: III. Effect of case-load on malnutrition related mortality - policy implications. Nutrition Journal, 17(1), 81. https://doi.org/10.1186/s12937-018-0382-6

Thanks to the last post for sharing the links.

I had seen them. Recently I was discussing these papers with a colleague who mentioned that mortality risk for WHZ only significantly increased at -3.5 WHZ (and that MUAC as admission criteria might still be preferable for detecting highest mortality risk and focusing resources on those at greatest risk).
I'm interested to know if anyone else has reviewed these papers and come to the same conclusion?