Hello,

Prevalence is firstly, the number of old and new cases

You need to take the number of cases of MAM and / or SAM obtained from screening and divide by the population of 6-59 months (or target of your protocol) affected by the problem. Then convert to %.

If I'm not mistaken.

Thank you

I think you need to think about:

(1) CASE DEFINITIONS : I think you should use the following case-definitions:

    GAM : MUAC < 125 OR oedema
    MAM : 115 <= MUAC < 125 without oedema
    SAM : MUAC < 115 OR oedema

(2) ESTIMATOR : If you have a lot of measurements then a classic estimator (i.e. cases / number screened) will work well. Smaller numbers might need PROBIT or classifications of prevalence using LQAS or similar.

Be aware that screening exercises are NOT surveys and that inclusion of a child can be subject to a number of selection biases particularly when central location screening is used. I think you need to be clear about methods and not pass your work off as a probability sample survey.

I hope this is of some use.