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