1) This indicator relies on an accurate age assessment. Since people often do not remember the exact dates of their children’s birth, the data collectors should always verify the child’s age. This can be done by reviewing the child’s birth certificate, vaccination card or another document; however, since many caregivers do not have such documents (and since they can include mistakes), it is essential that your data collectors are able to verify the child’s age by using local events calendars. Read FAO’s Guidelines (see below) to learn how to prepare local events calendars and how to train data collectors in their correct use.
2) Some countries may be using old cut off points (such as 120/ 110mm) as opposed to the WHO currently recommended 125/ 115mm. If you work in a country using older standards, report the results according to the older as well as the more recent standards. Always record the exact circumference (in mm), not just whether it is below or above the cut off point.
3) Prevention-oriented projects should use this indicator only if their strategy is likely to have an impact on the nutritional status of the target population. If your project is too short or focuses, for example, primarily on improving agricultural production, use less ambitious indicators measuring, for example, nutritional intake (such as Minimum Dietary Diversity) or specific nutritional practices.
4) In many countries, acute malnutrition is prone to significant seasonal differences (e.g. ranging from 5% in the months following the harvest to 11% before the harvest). Therefore, if you need to compare your baseline and endline data to assess the result of your work, ensure that the data is collected at the same time of a year, otherwise you will receive two sets of data which say very little about the change your project has (not) achieved.
5) Since the differences in the prevalence of acute malnutrition are often very small (e.g. from 7% to 5%), MUAC-based surveys need to use a very small margin of error (2-3%), using a large sample of children. With a larger team of measurers, MUAC data for a survey can be collected within 6 - 8 working days (training incl. piloting can be done in 1-2 days). To ensure maximum quality, use the guidance recommended below; if required, contract an in-country or headquarters-based advisor to design methodology, train your team and supervise the survey quality.