Dear Mija,
Defining emergencies based on MAM or SAM thresholds was proposed a long time ago. The idea was to help to decide when the number of SAM children requiring inpatient treatment was large enough to open therapeutic feeding centres (TFC). This was enshrined in the WHO 2000 document on nutrition emergency which said that TFC should be opened when the prevalence of WFH <-2 was above 10% with variations with the presence or absence of aggravating factors (1). Note that these thresholds to decide about the need for TFCs were based on moderate wasting levels, not on SAM prevalence. I guess the rationale for this is that standard nutritional surveys are not suitable to give a precise estimate of SAM prevalence for reasons explained by Brad Woodruff in another post we received this morning.
Personally, I am not in favour of having a SAM emergency threshold.
First, as discussed above, prevalence surveys are quite unreliable when estimating the number of SAM children to be treated, first again because they are not suitable to give precise SAM prevalence estimates, and second, because the number of children to be treated is related to incidence, not prevalence, and the conversion of prevalence to incidence is quite problematic as shown by quite a few recently published articles (2) (3) (4) (5) (6). There is more work going on, with much large number of surveys and which will be published soon, highlighting even more the problems of this conversion.
Second, and at a more fundamental level, I am not sure this idea of threshold, going back to the TFC days, is really relevant now that CMAM is the standard practice. Opening a TFC was something really mobilising huge resources and it was a decision which had to be taken only when one was confident TFCs would be used at full capacity. CMAM programmes can be started with low initial investment and there is no rationale to wait for an emergency threshold before treating SAM cases. All this was discussed in a very good paper published a few years ago in Field Exchange by Peter Hailey and Daniel Tewoldeberha (7). I suggest you have a look at this paper questioning the traditional use of thresholds and making the case for a new approach much more elegantly than I can do it in a short post here.
A final remark. Among obesity specialists, it is well recognised that the same BMI thresholds should not be used in different populations to define obesity due to differences in body frame and shape (8). The same debate is not really open in the malnutrition area, but I suspect the same rationale questions the use of WFH to define acute malnutrition. This would question even more the use of WFH thresholds to define nutritional emergencies.
1. World Health Organization. The management of nutrition in major emergencies [Internet]. 2000. Available from: http://www.who.int/nutrition/publications/emergencies/9241545208/en/
2. Isanaka S, Grais RF, Briend A, Checchi F. Estimates of the duration of untreated acute malnutrition in children from Niger. Am J Epidemiol. 2011;173:932–40.
3. Deconinck H, Pesonen A, Hallarou M, Gérard J-C, Briend A, Donnen P, Macq J. Challenges of Estimating the Annual Caseload of Severe Acute Malnutrition: The Case of Niger. PloS One. 2016;11:e0162534.
4. Isanaka S, Boundy EO, Grais RF, Myatt M, Briend A. Improving Estimates of Numbers of Children With Severe Acute Malnutrition Using Cohort and Survey Data. Am J Epidemiol. 2016;184:861–9.
5. Bulti A, Briend A, Dale NM, De Wagt A, Chiwile F, Chitekwe S, Isokpunwu C, Myatt M. Improving estimates of the burden of severe acute malnutrition and predictions of caseload for programs treating severe acute malnutrition: experiences from Nigeria. Arch Public Health Arch Belg Sante Publique. 2017;75:66.
6. Dale NM, Myatt M, Prudhon C, Briend A. Using cross-sectional surveys to estimate the number of severely malnourished children needing to be enrolled in specific treatment programmes. Public Health Nutr. 2017;20:1362–6.
7. Hailey P, Tewoldeberha D. Suggested New Design Framework for CMAM Programming. :4. Available at: https://www.ennonline.net//fex/39/suggested
8. Hruschka DJ, Hadley C. How much do universal anthropometric standards bias the global monitoring of obesity and undernutrition? Obes Rev Off J Int Assoc Study Obes. 2016;17:1030–9.