Is there a minimum level of SAM, under which it is not worthwhile to do a coverage assessment, because of the difficulties in finding cases? Integrated programs within local health facilities often fall within this category.
In such settings, stages 1 and 2 of SQUEAC can be done. This will provide a lot of information regarding barriers to coverage, treatment seeking behaviours, program performance, program outreach, etc. (stage 1) and identify issues with spatial coverage (stage 2). It can then be decided whether a stage 3 survey is needed (which is often not the case).
Cases can be hard to find if prevalence is low but wasting is often a "hidden problem" (i.e. a problem that is undiagnosed or not recognised). Data from prevalence surveys may underestimate prevalence due to families hiding sick children and because the Population Proportional Sampling (PPS) sample tends to exclude children in smaller communities (where the SAM cases may be).
It is common to conduct coverage surveys (like CSAS, SLEAC, or stage 3 SQUEAC) during "lean seasons" to make it easier to find cases. SQUEAC stages 1 and 2 do not need large sample sizes and can be conducted when prevalence is low and still yield useful information.
Guevarra E, Norris A, Guerrero S and Myatt M, Assessment of Coverage of Community-based Management of Acute Malnutrition,
CMAM Forum Technical Brief July 2012, Version 2: September 2014. Accessible online here