Buenas tardes. Excelente comentario. En la práctica, cuando se atiende un número grande de pacientes y con grandes distancias que recorrer entre comunidades, realmente debería simplificarse el método, en aras de optimizar el tiempo y ampliar la cobertura. En nuestras actividades de campo, en La Guajira colombiana, hemos observado que no existe diferencia en las mediciones, cuando se determina el punto braquial medio "al ojo" y luego son comparadas con mediciones en las que se utilizó el método tradicional. 

Por otro lado, teniendo en cuenta las fases del proceso de lateralización y las edades a las que estas suceden, considero que no tiene mayor repercusión clínica que se mida, indistintamente, uno u otro  brazo.

Automatic translation: 

Good afternoon. Excellent comment. In practice, when a large number of patients are being seen and with great distances to travel between communities, the method should really be simplified, in order to optimise time and expand coverage. In our field activities, in La Guajira Colombia, we have observed that there is no difference in the measurements, when the mid brachial point is determined "by eye" when compared with measurements in which the traditional method was used.

On the other hand, taking into account the phases of the lateralization process and the ages at which they occur, I consider that it has no great clinical repercussion that one or the other arm is measured interchangeably.

Hi Colleen,

I am not up-to-date with the evidence you mentioned, and I would greatly appreciate it if you could share some links or documents to such evidence.

The only reference I am aware that tried to provide an answer to the question of which side to measure was a chapter by Reynaldo Martorell et al, published as part of the 'Anthropometric Standardization Reference Manual' by Timothy Lohman, first published in 1988. Follow this link for a scanned copy of the chapter.

In that chapter, Reynaldo did find differences between arms, although these were small, with the right arm been bigger. Nonetheless, they concluded that the choice of side matters little because the difference between arms is small when compared to measurement error.

In my opinion, standard procedures help to disentangle signal from noise, and different measurers have different levels of noise and different situations require different clarity of signals. I do not think that one should expect that mothers/caregivers at home undertake MUAC measurements with the same degree of standardisation than community health workers collecting MUAC data for research purposes.

I hope the above is useful.

Colleen has this right ... the work has (mostly) been done by ALIMA as part of their work using mothers to screen their own children for SAM using MUAC. A number of other NGOs have, I think, adopted this approach.

We work in a field that can be slow to innovate. MUAC seems to have become something of a "cause celebre" for reactionaries in our field who spread FUD (fear, uncertainty, doubt) about the use of MUAC which has tended to delay uptake and innovation.

The original work is here.

Follow-up work on operationalising MUAC by mums is here.

I agree with Carlos about signal and noise in measurements. I think that the design of MUAC tapes in common use can contribute to noise and can give us a distorted signal due to systematic bias in measurements. ACF did some work on the design of MUAC classification devices for MUAC by mums and used a MUAC tape design that was designed to reduce noise which performed well. You can read about this work here.

Ther are a number of previous discussions about this issue in these pages. Try seaching for (e.g.) "MUAC left arm" using the search box (should be top-right on this page).

I hope this is of some use.

Hi colleagues

I have a question here:
I am wondering why MUAC is not used in assesment of nutritional status for children aged less than 6 months, while Z - Score is used for nutritional assesment for the age group 0 - 59?         

Hi Fahim

There have been several studies validating MUAC for infants under 6 months in Africa, but none yet in Asia. MUAC performed better in predicitng mortality than WLZ however the WHO would like to provide a global guideline, hence the need for Asian data.

Despite the lack of WHO guidance, people are beginning to use MUAC in the field for infants under 6 months, usually in a way that can be assessed and generate information on case loads, approrpiate interventions and outcomes.

BTW, research is now increasingly showing that WAZ is as good as MUAC in predicting mortality in this age group, both far better than WLZ. WAZ has some advantages in terms of integration with growth monitoring etc. On the other hand, MUAC is cheaper and more portable, but less familiar.

Kind regards

Jay

Hi there

For the experience in the field work MUAC is reliable and easy to use. In one of our nutrition program in partnership with UNICEF we were using MUAC as the only admission creteria for children 6 - 59 months of ages and the programme worked very well with good results in terms of existing them in the program. We are using MUAC for discharge too, because when you admit the child with MUAC <115cm and discharge with MUAC > 115.5cm to TSFP program continue the supplementary treatment there and discharge home when MUAC reaches >12,5cm in two consecutive visits.

Paul

Thank you so much Dr. Jay for these information and for your reply

Fahim