MUAC is a good surveillance tool. It meets the criteria of simplicity, acceptability, cost, objectivity, quantitativeness, age-independence, precision, and accuracy required of a case-defining indicator for surveillance better than W/H. See: http://www.who.int/nutrition/topics/backgroundpapers_A_%20review.pdf for a (pretty) full discussion. André Briend and colleagues: http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_5/b_fdi_23-25/30635.pdf have looked at this and conclude that weight change, MUAC, and W/H respond well (this was in response to flooding in Bangladesh). The decision between (e.g.) MUAC and W/H can be informed by practicality. Since they both work and MUAC is quicker and cheaper it would make sense to use MUAC. I think that 3 months the longest interval between measurements that would be useful. I would prefer 1 month. There are clever things you can do with surveillance systems to reduce costs. I suggest that you contact SC-UK or ACF for a copy of their HUMS guideline which has a small sample surveillance component using both weight change and MUAC. The dumbest thing is to do a series of SMART type surveys (far too costly). The use for percentage weight gain in CMAM programs was due to a few things. CMAM is not restricted to emergency use but to be run in primary healthcare centres in both emergency and development settings. Weight-for-height cannot be used for either admission, monitoring, or dicharge because ehight boards ar enot standard clinic equipment and the IMCI sylabus does not cover height measurment or the W/H lookup. At the time these decisions were being made (2005/6/7) there was little data on MUAc reponse to treatment so percentage weight gain was adopted as a "stop-gap". Percentage weight gain is not an ideal measure because the severest need to gain the least weight to reach discharge. This is the opposite of what is needed. Experience has shown that it is probably safe at 15% or 18% weight gain. More data on MUAC response to treatment is available and this shows that MUAC responds in a similar manner to weight. The belief that MUAC does not respond rapidly is mistaken. It was an assumption made to fill in an absence of data. It is quite easy to see how the mistake was made. Moving from (e.g.) 108 mm to 125 mm is a 17 mm difference in circumference bit only a 5 mm difference in diameter which might be difficult to spot without measurment. Work is currently underway to test the safety of MUAC discharge criteria. |