Work on prevalence threshold used to classify the severity of malnutrition in populations has concentrated on the 6-59 month age group. GAM prevalence in this age group is seen a a "canary in a coalmine" or early warning indicator and hase been used for this purpose for many years. Looking at key documents such as IPC Tools and Procedures for Classification of Acute , you'll see thresholds for GAM in there. Some women indicators (e.g. MDDW, anaemia, vitamin A deficiency) which measure "contributing factors" are also included. You'll find thresholds for these in WFP and WHO publications.

The IPC technial manual has a women indicator for nutritional status based on BMI < 18.5. Prevalence thresholds can be seen in Table 9 on page 36. BMI is a problematic measure as it is difficult to measure, strongly affected by body shape, and unsuited to use with pregnant women. I would use MUAC (< 210 mm or < 230 mm) and the IPC/WHO prevalence thresholds (which look a bit high to me).

I hope this is of some use.

Dear Mark,

Thanks for your explanations, nevertheless my question was more on what prevalence is considered of public health concern in PLW’s? For instance, using your example of IPC AMN, when it comes to children, GAM by WHZ >5% is an alert situation. Is there any guideline, maybe from WFP, about this? If my MUAC prevalence is of 6.0%, what does it mean in terms of public health impact?

Thank you. 

Sorry not to have been of more help. There is a number of guidelines available. I tend to use IPC as a current synthesis of these. You might use the IPC thesholds for BMI < 18.5.

PLWs are often targets for supplementary feeding and it seems likley that WFP might have a guidline that you can use.

In terms of impact ... low MUAC in mothers is associated with poor birth outcomes for both mothers and children and, for children, these are with poor outcomes after birth.

We tend to use GAM in chidlren aged 6-59 months as a "canary in a coalmine" or "early warning" indicator and would use that to trigger interventions. It would be very sensible (e.g.) to start supplemenation of PLWs with IPC classifications 2 and above. 

Thanks very much Mark. This was of some use. I will try to see if I can get some WFP guidelines about this. If someone has it, I would be more greatful if you can share with me. anyone? 

Thanks. Tomas