There has been a discussion about the use of ONLY MUAC as an admission and discharge criteria (http://www.en-net.org/question/468.aspx). Although I understand the challenge in the use of scales and heightboard in a challenging/demanding environment like POC in South Sudan, I wonder if the use of ONLY MUAC for admission and discharge of MAM cases is a RESOURCE issue. Just like the case in Ethiopia? (i.e., in Ethiopian CMAM guideline, SAM admission <11cm and discharge >=11cm). I have confusion…. 1. When using ONLY MUAC as an admission and discharge criteria, we left out those children who are malnourished with WHZ criteria. Are those children with WFH z-score: < -2 to = -3 not malnourished? If we think they are malnourished as per the available guidelines/evidence, is it ETHICAL not to include them in the programme (due to the impact in their development)? Or is there a guidance note to focus on programmes aiming at reducing malnutrition associated with mortality? 2. Regarding the admission and discharge criteria for malnourished children in Ethiopia (i.e., SAM admission <11cm and discharge >=11cm and MAM admission >=11cm and discharged at <12cm): are those children between >=11cm and <11.5cm, not severely malnourished? Are they not at high risk of mortality? If so, is it acceptable to exclude children >=11cm and <11.5cm from the OTP/SC services in an attempt to minimize resources? 3. There is a work in progress in South Sudan to use only MUAC as admission and discharge criteria for both SAM and MAM children? I understand children malnourished with MUAC are at higher risk or mortality, but how can we ensure children malnourished with WHZ criteria grow-up to a healthy adult? Is there any international consensus/guidance note on the options to alter these criteria to suit certain context (unless it’s a research?) Appreciate your thoughts!
WRT (1) : This has been covered in [url=http://www.en-net.org/question/1915.aspx]this thread[/url]. I'd add a couple of things: (a) The question is not really about "malnourished" but about mortality risk that can be changed. WHZ doesn't do the mortality bit very well. In fact it is worse at this than any other crude anthropometric indicator. You should be treating low HAZ kids and low WAZ kids before even thinking about low WHZ kids. (b) Ethics are usually very complicated and ethical conclusions usually depend on perspective. As a public health practitioner I tend to subscribe to a utilitarian ethical model. Put simply, a utilitarian ethic aims to deliver "the most good to the most people". The "most people" is what we might call high cure rates and high coverage. We know that WHZ cannot be done at high coverage. WRT (2) : CMAM programs in Ethiopia use MUAC < 110 mm for admission. I believe they do this to keep program numbers manageable and program costs such that they can offer CMAM as a universally available service. Mortality risk increases with decreasing MUAC so the MUAC < 110 mm kids will be at high risk (i.e. in more need of treatment and less likely to recover spontaneously) compared to the 110 mm <= MUAC < 115 mm children. It is also important to note that MUAC tends to follow a quasi-normal distribution. This means that small changes in admission criteria can lead to very large changes in numbers of eligible children. For example, with a mean MUAC of 145 mm with SD = 15 mm we'd expect a prevalence for MUAC < 110 mm of about 1% but a prevalence of MUAC < 115 mm of about 2.3% (i.e. program numbers could more than double). With these things in mind the Ethiopian decision looks like sensible rationing of services. In low resource settings (and this is where we usually work) it can be ethically acceptable to ration. In many cases non-rationing can lead to misdirection of resources and low coverage. I am not suggested that these are easy or pleasant decisions but they are decisions that we need to face up to. I think the MUAC >= 110 mm threshold for discharge is too low unless the discharge is to a "bridging program" such as SFP (this is often the case in Ethiopia). I would use a higher threshold for discharge to the community with no nutritional support and no monitoring. Work I have been involved in (in press and [url=http://www.cmamforum.org/Pool/Resources/MUAC-safety-FANTA-2014.pdf]here[/url] indicates that discharge to the community at MUAC >= 125 mm is safe. WRT (3) : Low WHZ kids with high MUACs are unlikely to be at high mortality risk and we can assume that most they will survive and grow up. The discordancy (i.e. low WHZ but high MUAC) is frequently seen in older children in populations with long legs and short and/or narrow trunks. Since the bulk of linear growth takes place in the limbs it is likely that these children are not stunted and may be among the healthiest of children. I think we can assume that most will grow up to become healthy productive adults. I do think there is a consensus in teh UN and amongst NGOs. It is that WHZ may be used "where it is feasible (capacity in terms of materials, time and trained human resources) without jeopardizing other essential health services". Since we usually operate in resource scarce settings this caveat will usually apply and we will not use WHZ. The use of WHZ in resource scarce setting is acting against this consensus. BTW : I think that you cannot divorce clinical and resource issues. I think doing so is unethical. We must seat our ethics in the world of what is necessary and practicable. We must be very clear about what this means and avoid ideological definition as far as we can. Rational use of resource is a lot more than mere cheapness. It is about delivering the most good to the most people. I think that MUAC only CMAM programming is a step in the right direction. I hope this is of some use.
Mark Myatt
Technical Expert

Answered:

9 years ago
Dear Anon’. I think the discussion around the suitability of using MUAC alone in SS combines a number of issues. Firstly, there is the significant disparity between % & # of MN cases identified using WHZ in comparison with MUAC. Where in many populations these measures provide estimates of MN within a few percentage points of each other, in populations with low Cormic index (such as across large tracts of SS) many organisations have been finding a substantial difference in prevalence’s and therefore the number of cases that would quality for SAM/MAM care. In the SS TWG of 1st Sept, UNICEF presented the findings from 180 SMART surveys between 2008-2015 to illustrate the significant difference between case detection using the two indicators, whereby WHZ in all bar a 4 assessments provided considerably higher rates/numbers of MN when compared to MUAC. Their analysis of 2015 data alone (Jan’-June’) from 26 SMART surveys, with 13,247 child inclusions for analysis, produced the following results: WHZ GAM 20.1% (CI 19.3-20.9%), MAM 15.7% (CI 15.1-16.4%) and SAM 4.4% (CI 4.0-4.7%) in comparison to MUAC GAM 9.1% (CI 8.4-9.8%), MAM 7.3% (CI 6.7-7.9%) and SAM 1.8% (1.6-2.0%). All 3 measures produced statistically significant differences. There are other independent reports reflecting the same trends i.e. the FANTA 2010 Situational Analysis in SS summaries that the prevalence of MAM identified with WFH by the WHO standards is 5–10 times higher than the prevalence identified with mid-upper arm circumference (MUAC) (MUAC < 125 mm).[4,5,6,7,28,29] For SAM, the prevalence rates have a much greater disparity: Prevalence of SAM in children identified with WFH and/or bilateral pitting oedema was 3–13 times higher than the prevalence identified with MUAC (MUAC < 110 mm). Therefore, the argument to use MUAC over WHZ here is not centre around ‘caseload’ and thus resources per se, rather the appropriate treatment of children ‘at risk’ of mortality associated with MN. However, the issues of resources will obviously also play a role, whereby prioritisation of high risk areas and individuals does need careful consideration where resources do not stretch to cover the entire population in need. We also encounter issues in SS such as staff capacity. The use of MUAC over WHZ is markedly easier and more widely understood as a measure, which results in improved adherence to protocols and ultimately a better quality of service. MUAC also provides to opportunity to include community based screening which has the potential to improve early case detection, increase referral rates and ultimately contribute to improved coverage. Hope this helps.

Answered:

9 years ago
Dear Dr Myatt, In your reply you speak of a lower chance of spontaneous recovery of children with a MUAC <110 mms in comparison to children with MUAC <115 mms. Does that mean there is spontaneous recovery - which I understand as recovery without specific intervention to treat SAM with energy dense foods but perhaps there has been some treatment of underlying infection or dietary counselling. Can you please guide me to any literature on children recovering "spontaneously"? I ask this specifically because in our own project area in India in the deltaic Sundarbans we see children whose parents refuse admission in Special Nutrition Units for all the usual reasons but children do get out of a Red MUAC with time when infections are treated and with dietary counselling. I have reference of a paper which highlights spontaneous recovery of children with MAM as per MUAC but not for SAM. Is such data available at all considering that we must not collect information on children if we cannot offer a service. ((Duration of Episodes of Untreated Acute Malnutrition in Children 6-59 Months as Observed During Monthly Growth Monitoring Sessions in South Bangladesh Monsurul Mohammed Hoq & Jillian Waid Bangladesh Terre des hommes Lausanne). Your responses as always are most educative and will be highly appreciated.
Charulatha Banerjee

Answered:

9 years ago
When I wrote that I was thinking of mortality observed in several historical cohort studies. The results for some of these are summarised in this plot: [img]http://www.brixtonhealth.com/muacMortality.png[/img] This shows the mortality observed in untreated children in five studies (it was very similar in the other studies - the plot capture the trend and variation without making a confusing plot). There is a great deal of consistency between the results of the five studies even though they had different follow-up times, treated accidental and violent deaths differently, and were done on different populations at different times by different teams. It seems reasonable, therefore, to combine the data using a simple average. Doing the calculations by eye ... At about MUAC = 110 mm we see mortality at about 220 / 1000 / year (i.e. about 22% of untreated children with MUAC = 110 will die within one year). At about 115 mm we see mortality at about 110 / 1000 / year (i.e about 11% of untreated children with MUAC = 110 will die within one year). There are three outcomes to a SAM episode (i.e. death, no-change, recovery). Data from other source suggest that untreated episodes lengths may be about 7.5 months (there is likely to be considerable variation). This means that at one year the bulk of episode outcomes will be either death or recovery. We can estimate recovery at about 78% for MUAC = 110 mm and 89% for MUAC = 115 mm. Since the estimates are from cohorts of untreated children we can assume that recovery is "spontaneous" (i.e. without a specific nutrition intervention). There are a few things to note: (1) An objection that is occasionally raised against the use of historical (1980s and 1990s) cohorts of untreated SAM cases to estimate current mortality in untreated cases is that there is considerable evidence of significant drops in childhood mortality over the years since the cohort studies were done. The objection is mistaken because the drops in childhood mortality are, in very large part, due to a combination of reductions in the incidence of the causes of childhood mortality, improvements in treatment coverage, and improvements in treatment efficacy. Current untreated SAM cases have the same disease as the SAM cases in the historical cohorts so reductions in incidence are not relevant. These cases are untreated so improvements in treatment coverage and treatment efficacy are also not relevant. The current SAM cases have the same disease and the same absence of treatment as the SAM cases in the historical cohorts. In the absence of additional and contradictory evidence on the case-fatality rates for untreated SAM at different levels of severity (which would now be unethical to collect) there is no good reason to believe that the current untreated SAM cases will not experience similar case-fatality rates to the SAM cases in the historical cohorts. (2) The rapid increase in mortality below about MUAC = 115 mm means that we need to concentrate case-finding and recruitment on catching cases early. These cases are easier to treat than more severe cases. Doing this needs case-finding with high spatial and temporal coverage. (3) I think your question assumes a 100% case-fatality rate. Compared to 100% those 11% and 22% estimates do not seem like very large numbers. To make a comparison ... untreated typhoid fever and untreated meningococcal disease have case fatality rates of between 10% and 20%. I hope this is of some use.
Mark Myatt
Technical Expert

Answered:

9 years ago
Hatty raises an important issue. The issue is also about the utility of WHZ in South Sudan. W/H measures such as WHZ and BMI are known to be strongly influenced by body shape. Cormic index (probably better known as "sitting to standing height ratio" or SSR in children) is one measure of body shape. SSR is known to be correlated with WHZ. This means that higher SSR is associate with higher WHZ and lower SSR is associated with low WHZ. SSR varies within populations and between populations: [img]http://www.brixtonhealth.com/wwSSR.png[/img]. This means that a given WHZ means something different in different populations. Look (e.g.) at the Mexican data in the plot above and you can see the a large part of the source of the the "Latino" overweight and obesity scare (remember higher SSR = higher WHZ). It works the other way round with some Sahel and Horn of Africa populations. This problem of "same value but different meaning in different places" is a reason to be wary of WHZ. The bulk of linear growth in children is in the limbs. This means that stunted children will have high SSR and high WHZ despite being at elevated mortality risk. This is another reason to be wary of WHZ - it systematically excludes young stunted children at high morality risk (these are usually picked up by MUAC). If a child is healthy and grows well they will have a low SSR and a low WHZ. In this case, WHZ will select heathy, older, and non-stunted children that do not need CMAM services. The debating point now is whether the WHZ+ but MUAC- children should be admitted to CMAM services. These children are very likely to be the heathy, older, and non-stunted children that do not need CMAM services. This misdirection of resources is another reason to be wary of WHZ. We have discussed ethical considerations above. I think that misdirection of resources in resource-scare settings is unethical. Resources squandered on treating a child that does not need treatment takes resources away from more pressing activities. Returning to the plot of SSR (above). In many settings the number of WHZ+ but MUAC - children are small. In other settings the number is very large. This often occurs when a number of factors (climate, altitude, diet, genetics, mating practices, &c.) come together to create a long-limbed / short trunked population. This is likely to be the case in South Sudan. I have done some work on this issue. You can read about that in [url=http://www.brixtonhealth.com/MyattBodyShape.pdf]this Annals of Human Biology article[/url]. I hope this is of some use.
Mark Myatt
Technical Expert

Answered:

9 years ago
Hi all, Thanks for that interesting discussion. With regards to WHZ I am still not sure whether it is really standardized for all children around the world or not.I have observed many ethnic/geographical variations of WHZ among different societies and countries.Thanks Mark for sharing your last document "The effect of body shape on weight-for-height and mid-upper arm circumference based case definitions of acute malnutrition in Ethiopian children". I think WHO might start to conduct another studies to standardize WHZ per ecological zone/regions.This will be more acceptable and will provide region-specific standards. I have observed some children between 48-59 months in Yemen who look normal (in nomadic areas) but their WHZ is below normal(SAM),they spent too much time in the programme and very little improvement in WHZ has been observed.They don't have any complications or diseases.Their MUAC was in MAM cut-off points. I reached to a provisional conclusion from the previous discussion with Mark and André and the current discussion, that in any nutrition program, I should focus on coverage of CMAM program using the simplest tool to detect malnutrition, MUAC tape, and to try to reach as much as possible of children to be screened (for MUAC and Odema) taking into consideration sphere standards.Also, to work to reduce the chance of refusal of admission as a result on incorrect readings by training of health workers .It is important also to train Community Health volunteers (CHVs) to screen children regularly-and mothers,where appropriate-; adopt a national CHVs policy and to establish a national screening strategy for all under 5 children. WHZ can still be functional at facility-based level, if we have well trained human resources, availability of scales,space and other resources. Our clinical suspicion and observations are also important in deciding the nutritional status of children . Second stage screening is better to be limited as it might affect programme acceptance by the community, SFP Programme can help in accepting higher cut-off point MUAC which will be very beneficial,it will include more children with acute malnutrition and will reduce the risk of death and further deterioration into SAM. A child with a severe wasting probably can't escape MUAC higher cut-off points and clinical observations/general appearance,I think. I can see that MUAC and WHZ are two different measurements and both tend to select a relatively different children,in my humble opinion as long as we don't have WHZ standard per specific region it is difficult to interpret SAM caseload based on WHZ , I think this will have an implications on SMART and other nutrition surveys that use WHZ to evaluate GAM. OTP/SFP MUAC Program will have cover a wide variety of children at early stages of malnutrition. We are still in need to conduct more studies to understand more on this issue. Thanks , Sameh
Sameh Al-Awlaqi

Answered:

9 years ago
I think there are problems with WHZ for each ecological zone / region: (1) This will be very expensive to do. Is is done ... some developed countries do have their own growth references but this may become less common as the WHO reference becomes more widely used. Separate growth standards are available for (e.g.) children with Down syndrome and Turner syndrome since children with these conditions follow growth curves that are quite different from children without these conditions. Growth references have been created to describe the expected growth patterns for several genetic diseases. I think that coverage of unique references will be patchy. (2) Philosophy - The WHO growth standards are supposed to reflect a sort of "ideal" growth. To move to a non-global standard would, I think, involve jettisoning the idea of an "ideal" for many ideals (a contradiction in terms). (3) We risk a sort of "normalisation" of poverty in which we except poor growth as acceptable. (4) Even in the same zone there will be variation in body shape so that the same WHZ threshold will mean different things in different children in the same zone. The same problem affects BMI. The solution used with BMI is to correct the crude (i.e. weight divided by height-squared) indicator for a measure of body shape (this is called the Cormic Index and is the sitting to standing height ratio). This is not often done as BMI is falling into disuse. A similar correction for SSR could be applied to WHZ. It requires another (and a difficult) measurement which requires more equipment (when I have done this we have carried a table or a 20 cm by 40cm by 50cm box with each team) and more calculations. We already know that we cannot do WHZ particularly well so adding another measurement and calculation is not a feasible option. A cruder approach might work. With BMI we use different case-defining thresholds in different locations (e.g. Japan, Singapore, and Hong Kong use different thresholds than those recommended by the WHO). We could do this with WHZ. In some setting we might use -3.5 for SAM and in others we might use -2.5 for SAM. This would address the ecological zone / region issue but not the individual variation issue.
Mark Myatt
Technical Expert

Answered:

9 years ago
Thank you very much Dr Myatt very much for your very clear response to my query and to the other useful responses in the posts that followed it.
Charulatha Banerjee

Answered:

9 years ago
That is true the discrepancy between the two methods in South Sudan is very high. In other countries, the discrepancy is not as such. So, as the epicentre of the issue is South Sudan, I think we should not rush to conclude from other countries experience. The evidences or researches globally seems based on cross sectional assessments or screenings. I think what we are lucking is programs or admission outcome data that shows comparison of both methods in terms of fatality rate, recovery, length of stay and so on. In South Sudan, some partners were requested to present their program data but still none of them are not yet ready to present. At the end of the day, there has to be evidence that show malnourished children below -3 Z-score and normal MUAC have no risk. We should not deny any service because of operational feasibility (resource, manpower).
Anonymous

Answered:

9 years ago
I do not think it sensible to adopt a position of "South Sudanese Exceptionalism" since the issue of WHZ being strongly influenced by body shape is present everywhere. The issue is large in the Sahel and the Horn of Africa and is, very probably, due almost entirely to long-limbed / short trunked body shapes. This is the body shape that predominates in low altitude, high temperature, and milk-consuming contexts. It is also present in South Asian, Southeast Asian, and some Oceanic populations where the problem is likely due to a narrow-trunked body shape. BTW ... I also do not think it sensible to adopt a position of "human exceptionalism". The body shape issues we see in human populations can (e.g.) be explained by Bergmann's rule and Allen's rule. Changes in limb lengths associated with air density, temperature, and diet have been observed in experiments with a diverse set of animal models. Arguments of exceptionalism are a great way of arbitrarily ruling what evidence we can accept and what evidence we can ignore. This is not the way rational medicine proceeds. I think we can use cross-sectional survey data to assess the magnitude of effect and to examine the relationship between body shape and WHZ. I think we can use program data but we have to be very careful when we do this as the sample will be self-selected and will likely be biased in all sorts of ways. A recent cohort study by MSF: [url=http://trstmh.oxfordjournals.org/content/107/5/319.abstract]Ali E, Zacharia R, Shams Z et al. Is Mid Upper Arm Circumference sufficient for case-finding and admission of children with severe acute malnutrition into nutritional support programmes in an urban slum in Dhaka, Bangladesh? Trans R Soc Trop Med Hyg, 6 February 2013[/url] ... also reported in FEX [url=http://www.ennonline.net/fex/47/muac]here[/url] looked at this issue. It followed up (three months) children with MUAC > 115 mm but WHZ <-3 not admitted to TFP and found almost all of the children (93%) either improved in nutritional evolution or maintained a status-quo after three months’ follow up, without receiving any nutritional treatment. Few needed admission to a nutritional programme, although several had medical conditions that required hospitalisation irrespective of nutritional status, and only one death (from TB) occurred. This looks to me like "evidence that show malnourished children below -3 Z-score and normal MUAC have no risk". I think we now need evidence to the contrary if we are to continue to resist moves to MUAC only programming.
Mark Myatt
Technical Expert

Answered:

9 years ago
Thank you Mark for sharing the recent cohort study from MSF. Three issues I’d like to add to Marks response above to the comments of Anon’ 81 - thank you for sharing your thoughts: 1) In addition to hundreds of surveys clearly illustrating the disparity between WHZ and MUAC in certain populations, we also have mortality data from the same data sources, supporting the argument that elevated rates using the measure of WHZ provide unrealistic, or inflated estimates of malnutrition, given consistently ‘normal’ mortality rates. For example, in Twic (SS), since January 2010 to February 2015, annual SMART surveys have yielded an average GAM (WHZ) of 18.6% (with variations from 16.5% - 20.9%), an average GAM (MUAC) of 7.8% (with variations from 6.0% - 9.1%), an average crude mortality rate (CMN) of 0.45 (with variations from 0.38 – 0.6/10,000/d) and an average under 5 mortality rate (U5MR) of 0.9 (with variations from 0.76 – 1.22/10,000/day). Mortality rates fluctuate around SPHERE's ‘normal’ rates for Sub-Saharan Africa and in no way support the ‘emergency’ rates of acute malnutrition estimated using the WHZ measure. These findings are not unique. In Twic, surveys over the same period averaged a GAM (WHZ) of 28.1%, a GAM (MUAC ) 7.0%, a CMR of 0.5/10,000/d and a U5MR of 1.2/10,000/d. In this last example, if we really had between a quarter and a third of the population estimated to be suffering from acute malnutrition, we would expect mortality rates to be significantly higher. 2) Regarding the issue of collating program admission and outcome data from existing partner interventions for use as an evidence base, to help guide decision making around the suitability of anthropometric measures: I believe the data yielded would have limited value. Mark has already pointed out that the samples data would be collected from would be self-selecting (those attending programs) and thus will likely be biased. I would like to expand here. Staff capacity is indisputably limited, staff numbers are low given the geographically huge catchment areas of health facilities and physical access to the field is often very poor meaning outreach activities including absentee & defaulter tracing are often seriously restricted. These issues result (in reality) in deaths going un-recorded. Systematically correct data collation is also a challenge whereby active and continuous support is essential to ensure a basic level of reporting is maintained, but errors often occur. Program adherence to OTPs/TSFPs are also affected by the populations perceived value of the products disseminated. For example if a cereal-based ration (with sugar and oil, sometimes pre-mixed, sometimes distributed as individual commodities) were provided, this might have a greater ‘value’ to the family than a ready to use food (RUF), thus these sorts of variables would also likely affect program compliance. There are also a whole host of logistical constrains that will also affect program compliance, including program access for beneficiaries and equally program staff, stock ruptures etc. Therefore, I feel the only way to conduct such a proposed investigation would be in a strictly controlled study-based environment ,with extremely well trained staff, rigorous support and oversight. However, we should be asking the question, is this sort of study necessary given the type of evidence Mark has shared. 3) Re. the final remark, ‘We should not deny any service because of operational feasibility (resource, manpower)’. Sadly resources and manpower absolutely ‘must’ be considered during program planning, this is a practical reality. There simply is not the funding available, or the skilled workforce in place to implement therapeutic care services with 100% geographical coverage. This however I believe is an issue aside from the main topic of the appropriate use of anthropometric indices to accurately estimate rates of acute malnutrition.

Answered:

9 years ago
Dear Colleagues, Have you seen this study : [url]http://www.ncbi.nlm.nih.gov/pubmed/25805273[/url] Please check and let me know what do you think about it. Regards, Sameh
Sameh Al-Awlaqi

Answered:

9 years ago
Thanks Sameh for sharing. it is interesting. it is good to have more such types of program related researches. if possible more prospective cohort studies so that different outcomes can be recorded. we have more than enough these cross sectional surveys.
Anonymous

Answered:

9 years ago
Dear Sameh, Thanks for flagging this paper. I could just access the abstract, not the paper. A word of caution. Studies based on programmes as this one are based on highly truncated samples which are not representative of the whole population. Hence, they are not suitable to make statements about the value of different indices to detect high risk children in the community. And the conclusion of the abstract remains rightly vague on this issue. As I mentioned in a previous post, MUAC < 115 mm will not identify all children who will die during follow up. Some children with MUAC slightly above 115 mm will be picked up by WFH <-3 and they are also at risk. Some will die of non malnutrition related causes. So adding WFH <-3 as selection criteria to MUAC < 115 mm alone will detect slightly more of these children who will die than MUAC <115 mm alone. The real question is “is this scheme better than increasing slightly the MUAC cut-off to select high risk children from the community ?” which is another easier option. Data from programmes following up highly truncated samples do not allow to answer this question as they did not follow in the community children with slightly higher MUAC truncated from the sample. Also, when considering the option of increasing MUAC cut off above 115 mm (and even more the option of adding WFH <-3), operational issues need to be taken into account. We do live in a world where resources for programmes are limited and we must concentrate our efforts to the most at risk. In my view, increasing MUAC cut off or adding WFH <-3 are ill advised as long as SAM treatment coverage for MUAC < 115 mm remains low. I hope this helps
André Briend
Technical Expert

Answered:

9 years ago
The article referred to is not open access. Just so all can see it ... I have uploaded it to [url=http://brixtonhealth.com/GrelletyE.PHN2015.pdf]here[/url]. The issue here is that it is very difficult to draw inferences from self-selected samples. Any use of program data is use of a self-selected sample because the subjects (or their carers) have decided to attend the program. The decision is a complex one and will be determined by many things (these are what we try to ascertain with SQUEAC coverage assessments). All you can say is that X and Y happened IN THIS PROGRAM. If the factors behind the decision to attend changed (as we know they do between programs) then X and Y might not happen. The paper does admit this: Several limitations of the present analysis warrant mention. We note that the study population represents a selected sample of the general population (i.e. children admitted to the MSF TFP). Therefore, the results are not representative of the population at large and do not allow a clear conclusion about the relevance of using WHZ in addition to MUAC to select those children who have the highest risk of death in the community. Unfortunately they do not explore the likely biases associated with their sample. There is also a program based selection bias. If (e.g.) WHZ was used at clinics and MUAC used in the community then we would expect high mortality in WHZ admissions because they had attend for an illness serious enough to prompt clinic attendance. WRT response ... if MUAC- / WHZ+ is a group with low WHZ due to long limbs (i.e. quite healthy children) then response would be low. I think it may be work looking at what we need to decide if WHZ is useful and what we have in the article. What we need is: (WHZ < -3 OR MUAC < 115 mm) AND in the community What we have is: (WHZ <- 3 OR MUAC < 115 mm) AND in the community AND in the viable catchment area for clinical services AND screened AND attended AND recruited AND retained AND ... All those ANDs are the issue. The more of them that there are, the less the cohort looks like the cohort we need (recall that AND excludes and OR includes). As you can see there are plenty of ANDs in what we have and this is just the obvious list. I think that what we have in this article this a very different group than you might initially have imagined. We cannot pretend that what we have is even close to what we need to decide the key question raised in this thread. Another BIG issue with this and similar studies is data quality ... I have seen quite a few MSF programs and I know that there record-keeping tends to be quite good. What we have is program data and this will almost always lack the stringency of research data. One key issue with operational data from CMAM programs is that non-attendance is usually classified as "default". The problem with this is that non-attendance may (e.g.) be due to deaths not detected, or default due to cure, or default due to non-response which is likely to have resulted in subsequent death. The default rate in this program was very high. This means that any estimate of the number of deaths in each arm of the study is highly suspect. I hope this is of some use.
Mark Myatt
Technical Expert

Answered:

9 years ago
As usual, thanks André BRIEND for your clarification. Of course, there could be issues on the research methods but it is not different from those similar program or hospital setup researches published so far. There has been lots of similar researches published and used as input for different consumptions. To me such research helps as a complementary to other similar findings and also will create an appetite for further researches.
Anonymous

Answered:

9 years ago
Thanks Anonymous 81,André and Mark for your contribution. I was trying to contact the author of that article. Thanks for sharing the article here. Regards, Sameh
Sameh Al-Awlaqi

Answered:

9 years ago
How about this? systematic review of evidences commissioned by WHO Roberfroid D et al. Background review. Utilization of mid-upper arm circumference versus Weight-for-height in nutritional rehabilitation programmes. 2013 Conclusion - There are indications that MUAC could be used adequately as a stand-alone criterion for SAM children to be admitted to and discharged from nutritional rehabilitation programmes. However, the evidence base is currently insufficient. More data are particularly needed on the risks of children with a low WHZ not treated for SAM where MUAC is used as a stand-alone criterion.
Anonymous

Answered:

9 years ago
This leaves me wondering what sort of evidence would satisfy you. The evidence from the MSF study from Bangladesh addressses this issue quite clearly. This is only one study but it is the only evidence we have on that particular aspect of the issue. I'd like there to be more evidence. The problem is, however, that when similar studies are proposed people raise ethical issues. This puts us in a position where concerned people like Anonymous 81 demand evidence but then deny others the opportunity to collect the evidence they demand. That's a neat way of winning an argument but it is not evidence-based medicine. If you need more evidence the why not collect it? I will help in any way that I can. I am also pretty sure that Andre will help with this too. I suggest, then, that we change the direction of this thread towards (1) defining the evidence that is needed, (2) working out how to collect such evidence (the MSF Bangladesh study might be a starting point for this), (3) get funded, and (4) do the work. Anyone intrersted in doing that?
Mark Myatt
Technical Expert

Answered:

9 years ago
Returning to the use of patient cohorts and continuing to use the what we need and what we have comparison. I think we need to be able to identify and recruit cases that if untreated would have a high mortality but it treated would be likely to survive. What the patients cohorts - as in Grellety et al. (2015) - have is a limited selection of treated cases. This is (almost) the exact opposite of what we need. The "almost" is because there may be some value in using the patient cohort data to investigate response. We do see marked responses in all groups. The problem here is that we have a self-selected sample so what we see may, in whole or in part, be due to a complex selection biases. Anonymous 81 is correct that there is value in having a broad range of such reports as not all biases will be present in all cohorts. The higher coverage programs would have fewer selection biases but these programs tend to prioritise MUAC and may allow WHZ admission from clinical services (so the WHZ kids are likely to be very sick). Note : There are also some methodological issues regarding the credibility of some of the null hypotheses in such studies but this is a separate issue.
Mark Myatt
Technical Expert

Answered:

9 years ago
Mark - we would certainly be interested in discussing research options/opportunities. I will email you separately now. Thnx

Answered:

9 years ago
Just looking at the numbers in the Grellety et al. article ... The conclusions are drawn from very small numbers. Looking at the top of their Figure 1 we see that from a total sample of 2205 children there are only 21 children in the MUAC+ / WHZ- group. This is the outcome of a selection process that has preferentially selected low W/H children. It is very difficult to generalise these results to a program model that selects low MUAC children.
Mark Myatt
Technical Expert

Answered:

9 years ago
More on the Grellety et al study posted a few days ago on this website. Grellety E, Krause LK, Shams Eldin M, Porten K, Isanaka S. Comparison of weight-for-height and mid-upper arm circumference (MUAC) in a therapeutic feeding programme in South Sudan: is MUAC alone a sufficient criterion for admission of children at high risk of mortality? Public Health Nutr. 2015 Oct;18(14):2575-81 This paper has a major problem of sample representativity. It can only create confusion in the context of community screening and should not be used for this specific discussion. It is based on a selection process which preferentially (ie almost only) selects low WFH children. Look at the top of the figure 1 of the paper. There is a gross imbalance of “discordant pairs”. Of the total sample of 2205 children, only 21 are in the cell low MUAC high WHZ (top right). And 1486 (70 times more !!) are in the high MUAC low WHZ (bottom left). This is not what we see in community screening. To better illustrate this point, here is a table comparing the percentage of children in different SAM categories in the Grellety paper and in a sample of 552 community based surveys collected by Mark and which he kindly shared with me for comparison. 552 surveys Grellety et al. MUAC < 115 mm and WHZ < -3 23% 32% MUAC < 115 and WHZ >-3 39% 1% MUAC > 115 and WHZ < -3 38% 67% So we have in the Grellety study a highly biased and truncated sample, not representative at all of what is seen in the community, with a gross under representation of low MUAC children. Given this imbalance, no wonder you observe more deaths in the low WFH category! No wonder that in this peculiar sample, most deaths were picked up by low WFH which is based on a sample 70 times bigger ! And no surprise that the low MUAC category missed so many deaths ! I guess the imbalance is due to the selection process used in this study, including a step whereby low MUAC short children (67 cm) are excluded. This eliminates from the low MUAC category the youngest children, slightly more girls, and also more of those who are stunted, i.e. those with the highest risk of death. This of course has a negative effect on the ability of MUAC to identify high risk children. So I suggest we forget this study for the current discussion on the identification of highrisk children. Arguably, the authors of the Grellety study acknowledge the lack of representativity of their sample in the section discussing study limitations but they fail to highlight the exclusion of the most at risk low MUAC children from their sample. And the comment they make on WFH picking up more high risk children than MUAC should in no way be extrapolated to the community. Many programmes use a height cut off in addition to MUAC to decide which children to treat, as was done apparently in the programme analysed in the Grellety paper. I have never seen a clear evidence based rationale for that. The main effect of this approach is to deny treatment to young stunted low MUAC children who have a high risk of death.
André Briend
Technical Expert

Answered:

9 years ago
Just following up with some data from a MUAC only program from Malawi in which we have been conducting research into the safety of MUAC discharge and MUAC response to treatment and infection during the treatment episode that used an age-based eligibility criteria (i.e. age between 6 and 59 months) with age determined (mostly) from child health cards. In this study, we have a median height (length in children aged 6 - 23 months) of 67.4 cm. In this program we would have excluded almost half of all children aged >= 6 months with MUAC < 115 mm if we had used the >= 67 cm eligibility criteria. To be clear ... we would have excluded many children who were both wasted and stunted and at very high mortality risk left untreated. I think the 67 cm is supposed to be some sort of proxy for age. The median WGS reference length for 6 month old girls is 65.7 cm and for 6 month old boys it is 67.6 cm. Using 67 cm as a proxy for 6 months for children not living in the ideal conditions of the WGS reference population would reject very many children aged 6 months and older. It seems to me that 67 cm is inappropriately restrictive for most settings we work with. Like André I am at a loss to see the rationale for the 67 cm threshold. If I were to pick a threshold it would (perhaps) be the 6 month - 3 HAZ threshold (that is 58.9 cm for girls and 61.2 cm for boys) but even that might be too restrictive. I agree with André ... the Grellety et al. (2015) study did not include many low MUAC children at high mortality risk. The described program left those kids to die outside of care.
Mark Myatt
Technical Expert

Answered:

9 years ago
Dear Moderator, I was wondering if you communicate with the authors, Grellety et al to share their opinion on the above feedback given By André and Mark. I also wish both André and Mark to say something on the Systematic review commissioned by WHO, posted above.
Anonymous

Answered:

9 years ago
Dear Kiross, Thank you for your message and suggestion. We have communicated with the authors to alert them to this discussion and invite them to comment. Best wishes, Tamsin
Tamsin Walters
Forum Moderator

Answered:

9 years ago
Dear all This is an intriguing,relevant and interesting discussion.I like the fact that the word "evidence" keeps coming up again and again.I hope this is not digressing or changing the food of the discussion, but I sometimes wonder whether the MUAC/WHZ could be one of the reasons why we continue to see high GAM based on WHZ where we clearly are using MUAC for admission.The MUAC results (clearly the more relevant in a programme where there is little or no WHZ for admission) becomes a footnote and "WHZ" our focus.I always wonder whether this may explain why we struggle to keep GAM levels low or to reduce them as we miss many of the children. Hopefully this subject will continue to generate more interest, objective analysis and a way forward.
Blessing Mureverwi

Answered:

9 years ago
Responding to anonymous 730 ... I do not buy into the premise of the argument here. Look at the Grellety paper which is being put forward as an exemplar from which we should be deciding policy. This has: Admission criteria Admissions (%) -------------------------- -------------- MUAC < 115 mm and WHZ < -3 32% MUAC < 115 and WHZ > -3 1% MUAC > 115 and WHZ < -3 67% -------------------------- -------------- That is 99% admissions by WHZ with 67% by WHZ alone. This program clearly focussed on WHZ admissions. Just to restate André's post with my quick analysis. We would expect a program giving EQUAL WEIGHT to MUAC and WHZ admissions to have something like: Admission criteria Admissions (%) -------------------------- -------------- MUAC < 115 mm and WHZ < -3 23% MUAC < 115 and WHZ > -3 39% MUAC > 115 and WHZ < -3 38% -------------------------- -------------- That is 77% admissions on MUAC. Warning : These figures are bassed on 553 surveys from 49 countries and we might expect some local variation. We do know that coverage can be hard to achieve with WHZ so a MUAC or WHZ program should see far fewer WHZ only admissions. I think we should (only briefly - this is a separate discussion) on the very poor evidence for the effectiveness and coverage of TSFP and FBP programs at preventing and treating MAM and preventing SAM. It seems likely that many of these programs will have a marginal effect on reducing GAM prevalence. The new supplementary products are good (i.e effective) but coverage remains weak. This translates to low impact regardless of admission criteria. Since WHZ is strongly influence by body shape and in South Sudan there is a large population with the low WHZ body shape we will probably never get GAM by WHZ below the stated 5% target. It is counter-intuitive but, because linear growth tends to concentrate in the limbs, as the situation gets better and stunting prevalence and severity decreases we can expect to see mean WHZ decreasing and the prevalence of GAM by WHZ increasing. I do agree with the need for an objective analysis. This requires us to define what would be useful and appropriate evidence (rather than any evidence that can be bent to support a point of view) and then to collect this evidence.
Mark Myatt
Technical Expert

Answered:

9 years ago

Just reviewing this thread ... someone asked about:

Roberfroid D et al. Background review. Utilization of mid-upper arm circumference versus Weight-for-height in nutritional rehabilitation programmes. 2013


The big problem, IMO, with this review is that it suggests that the type of exemplified by the Grellety study (discussed above) would provide appropriate and useful evidence (this is the in the concluding sentence of the review). I think, given the problems with this type of evidence (discussed above), that the review has not been very useful. I fear that it has inspired a lot or not very relevant work ans sown confusion.

Mark Myatt
Technical Expert

Answered:

9 years ago

Dear Kiros,

You asked me to comment the systematic review:

Utilisation of mid-upper arm circumference versus weight-for-height in nutrition rehabilitation programmes: a systematic review of evidence.

http://www.who.int/nutrition/publications/guidelines/updates_management_SAM_infantandchildren_review1.pdf

The current discussion is whether MUAC alone or MUAC and WFH should be used to select children in need of treatment. I am not sure this is really what is discussed in this WHO working document.

To choose between WFH and MUAC as admission criteria, you have to give preference to the indicator which selects from the community children with the highest risk of death and which are most likely to respond to treatment (currently, RUTF + antibiotics).

This issue was investigated in 6 different community based studies examining ROC curves (sensitivity plotted against specificity for a whole range of cut-off) of MUAC and WFH to predict deaths (Bairagi, 1981) (Alam et al., 1989) (Vella et al., 1994) (Van den Broeck et al., 1996) (Briend et al., 2012) (Mwangome et al., 2012). All of them showed that MUAC had a ROC curve above that of WFH. In several of these studies, a prediction as good as that of WFH could have been obtained by just tossing a coin. A review in 1994 on the relationship between anthropometry and mortality based on studies available at that time concluded that “the most consistent observation is that WFH is the least effective predictor of mortality” (Pelletier, 1994).

Before going to MUAC, one has to check that selected children respond to treatment. The response to treatment of children selected by MUAC compared to those selected by WFH has little been investigated. The WHO working document, however, quotes 4 studies examining this response. None of them suggest that children selected by MUAC respond differently.

So in summary, there is consistent evidence that MUAC better selects high risk children who also respond to treatment. The conclusion is clear: we should go for MUAC.

None of the community studies on anthropometry and mortality is mentioned in the WHO working document, and the association between MUAC and risk of death not highlighted, although this association is behind the current move of programmes towards MUAC, independently of its easiness of use in the community. The only reference to mortality in this WHO working document is based on treated children with an unknown representativity of the examined sample compared to the overall population. Also, there is no mention of the specificity of WFH compared to MUAC, which considerably weakens the conclusion of the analysis. A randomly allocated variable not associated with mortality can predict all deaths in a sample if a very low specificity is accepted.

The WHO working document, and also two recent papers (Isanaka et al., 2015) (Grellety et al., 2015) raise the question of children of the risk of death of children with WFH <-3 and MUAC > 115mm, currently not selected by standard MUAC only programmes. And indirectly advise for possibly using both indicators. I don’t think, however, this is the correct approach to improve the identification process (Briend et al., 2012). ROC curves show that increasing the MUAC cut off is will be more effective and we also know this will be programmatically much easier. So I suggest that instead of continuing this sterile discussion about including children with WFH <-3, we should consider increasing the MUAC cut off. Children with a MUAC of 116 mm are hardly better off than those currently selected and regrettably there is no discussion about the opportunity to treat them as well, although MSF in different programmes used this approach successfully (see: http://files.ennonline.net/attachments/2401/FEX-50-Web-Final.pdf p 108).
This option of increasing the MUAC cut off instead of keeping WFH < -3 is not discussed in the WHO working document.

A frequent objection to increasing the MUAC cut-off is that this will increase dramatically the number of patients admitted for treatment. This is true, there will be an increase of patient numbers, and the decision has to be thought carefully, taking into account treatment capacity. The effect on treatment coverage has to be assessed. However, adding children with WFH <- 3 in a MUAC<115 mm only programme would also increase the number of patients by about 60%. See again the table derived from 522 surveys collected by Mark (with about 500 000 children in total) I mentioned in a previous post on the breakdown of different categories of SAM children:


MUAC < 115 mm and WHZ < -3 23%
MUAC < 115 and WHZ >-3 39%
MUAC > 115 and WHZ < -3 38%

One could easily increase the MUAC to make it more inclusive, increasing the number of high risk children detected, i.e. increasing the sensitivity of screening, without going beyond the patient numbers that you would get by also including all children with WFH < -3.

Ideally, the MUAC cut off for SAM treatment should be based on risk assessment and response to specific SAM treatment. We know that the risk of death no more decreases beyond 125 mm (Myatt et al., 2006). We have no information on a cut off based on response to treatment, however. Even if children with a MUAC 120-125 mm are at a high risk, this does not mean they need a specific treatment with RUTF, they may well respond to a less expensive food supplement or an adequate diet based on local foods, with mineral and vitamin supplements, if needed. More research is needed on this.

The WHO working document also ends up suggesting that analysing current programmes will help to decide if it is relevant to use WFH<-3 as additional admission criteria or if MUAC <115 mm alone is sufficient. This statement has to be qualified, as this is correct only if SAM children treated are representative of SAM children seen in the community, something very difficult to achieve. For this, you have to make sure that different categories of children are referred to treatment in the same way and have the same treatment seeking behaviour. A real challenge. The Grellety et al. study should be an eye opener in this respect as it is based on a sample from which nearly all high risk low MUAC children were excluded and no conclusion relevant to admission criteria can be obtained from it (see my previous post). In addition to that, data from treated children are difficult to interpret. After a few days, there are few deaths and many of them are unrelated to malnutrition if treatment is correctly implemented.

An additional limitation of the data analysis of current programmes is that most of them are not adapted to analysing the alternative and more attractive option of increasing the MUAC cut off. Current programme do not screen these children and all children who have a MUAC > 115mm and WFH <-3 are censored.

I let you appreciate the relevance of this WHO document in light of these comments. Of note, I fully support Mark’s statement that well known WFH uncritical supporters are overrepresented among the authors of this WHO working document. The lead author himself has even just published an article highlighting that MUAC < 115 mm does not identify correctly children with WFH <-3 (déjà vu hundreds of times !!!; just wondering how this can still be published) and rejects the use of MUAC on this basis (Roberfroid et al., 2015). Of course, MUAC and WFH do not select the same children, else these two indices would be just as good to assess the risk of dying, whereas MUAC is better. Interestingly, the only reference to mortality in this paper is based on the Grellety study, used to claim that WFH <-3 is much better to detect children who are going to die, but failing to mention that the selection process eliminated virtually all high risk children with a MUAC < 115 mm. No mention either of community based studies.

A personal note to end up. My first papers on MUAC and mortality were published in 1986 (Briend and Zimicki, 1986) (Briend et al., 1986), nearly 30 years ago now. Since then, it has been confirmed many times that MUAC is very good to identify high risk children, much better for that than WFH and easy to implement at the community level, even by mothers (Blackwell et al., 2015). I have enough of the ongoing discussion, I think we should stop saying we have not enough evidence for moving to MUAC. I am rather depressed to see this repeated at the end of this WHO working document which fails to mention the evidence in favour MUAC being a better predictor of the risk of death. I am also upset to see this repeated uncritically in this forum, including by the moderator, neglecting the evidence. Those who want more evidence should read the relevant literature, and avoid relying on poor documents censoring the evidence. Else, they should describe the type of additional study they need to be convinced, if ever, it is just too easy to say there is not enough evidence beyond limits. As shown by the data of the Grellety study, a dogmatic attitude in favour of low WFH children eliminates from treatment many high risk children and results in many unnecessary deaths (by the way, the authors of the Grellety study examined data from an ongoing programme, they did not design it as far as I know and should not be held responsible for the selection process which denied treatment to those most at risk and for the excess of deaths which resulted from this). I am afraid the ongoing debate on whether or not to include children with MUAC > 115 mm and WFH <-3 is counterproductive and diverts our attention from the important reconsideration of current MUAC cut-off in relation to response to treatment. And also diverts on attention from the broader and even far more important issue of access to treatment and current low programme coverage. All this leads to more preventable deaths still occurring among high risk children who remain untreated. No wonder quite a few of us have difficulty in keeping calm in this debate which has been going on for too long.

I hope this helps,

André

References

Alam, N., Wojtyniak, B., Rahaman, M.M., 1989. Anthropometric indicators and risk of death. Am. J. Clin. Nutr. 49, 884–888.

Bairagi, R., 1981. On validity of some anthropometric indicators as predictors of mortality. Am. J. Clin. Nutr. 34, 2592–2594.

Blackwell, N., Myatt, M., Allafort-Duverger, T., Balogoun, A., Ibrahim, A., Briend, A., 2015. Mothers Understand And Can do it (MUAC): a comparison of mothers and community health workers determining mid-upper arm circumference in 103 children aged from 6 months to 5 years. Arch. Public Health Arch. Belg. Santé Publique 73, 26. doi:10.1186/s13690-015-0074-z

Briend, A., Dykewicz, C., Graven, K., Mazumder, R.N., Wojtyniak, B., Bennish, M., 1986. Usefulness of nutritional indices and classifications in predicting death of malnourished children. Br. Med. J. Clin. Res. Ed 293, 373–375.

Briend, A., Maire, B., Fontaine, O., Garenne, M., 2012. Mid-upper arm circumference and weight-for-height to identify high-risk malnourished under-five children. Matern. Child. Nutr. 8, 130–133. doi:10.1111/j.1740-8709.2011.00340.x

Briend, A., Zimicki, S., 1986. Validation of arm circumference as an indicator of risk of death in one to four year old children. Nutr. Res. 6, 249–261. doi:10.1016/S0271-5317(86)80129-4

Grellety, E., Krause, L.K., Shams Eldin, M., Porten, K., Isanaka, S., 2015. Comparison of weight-for-height and mid-upper arm circumference (MUAC) in a therapeutic feeding programme in South Sudan: is MUAC alone a sufficient criterion for admission of children at high risk of mortality? Public Health Nutr. 18, 2575–2581. doi:10.1017/S1368980015000737

Isanaka, S., Guesdon, B., Labar, A.S., Hanson, K., Langendorf, C., Grais, R.F., 2015. Comparison of Clinical Characteristics and Treatment Outcomes of Children Selected for Treatment of Severe Acute Malnutrition Using Mid Upper Arm Circumference and/or Weight-for-Height Z-Score. PloS One 10, e0137606. doi:10.1371/journal.pone.0137606

Mwangome, M.K., Fegan, G., Fulford, T., Prentice, A.M., Berkley, J.A., 2012. Mid-upper arm circumference at age of routine infant vaccination to identify infants at elevated risk of death: a retrospective cohort study in the Gambia. Bull. World Health Organ. 90, 887–894. doi:10.2471/BLT.12.109009

Myatt, M., Khara, T., Collins, S., 2006. A review of methods to detect cases of severely malnourished children in the community for their admission into community-based therapeutic care programs. Food Nutr. Bull. 27, S7–23.

Pelletier, D.L., 1994. The relationship between child anthropometry and mortality in developing countries: implications for policy, programs and future research. J. Nutr. 124, 2047S–2081S.

Roberfroid, D., Huybregts, L., Lachat, C., Vrijens, F., Kolsteren, P., Guesdon, B., 2015. Inconsistent diagnosis of acute malnutrition by weight-for-height and mid-upper arm circumference: contributors in 16 cross-sectional surveys from South Sudan, the Philippines, Chad, and Bangladesh. Nutr. J. 14, 86. doi:10.1186/s12937-015-0074-4

Van den Broeck, J., Eeckels, R., Massa, G., 1996. Validity of single-weight measurements to predict current malnutrition and mortality in children. J. Nutr. 126, 113–120.

Vella, V., Tomkins, A., Ndiku, J., Marshal, T., Cortinovis, I., 1994. Anthropometry as a predictor for mortality among Ugandan children, allowing for socio-economic variables. Eur. J. Clin. Nutr. 48, 189–197.

André Briend
Technical Expert

Answered:

9 years ago

To all following this thread,

For those who are still on the fence, an abridged summary:

- It is accepted that MUAC is a better predicator of mortality
- It is well understood that MUAC is a far simpler and cheaper tool to use in practical settings
- The generalised understanding of a MUAC tape is far easier to grasp, especially when colour coded, vastly simplifying programming
- Mothers have been shown to be able to use and effectively refer their children using MUAC tapes (Blackwell et al., 2015) thus having the potential to HUGELY increase coverage - a commonly overlooked and INCREDIBLY important issue when we're trying to treat maximum numbers of those 'at risk'
- The WHO working document references 4 studies illustrating that the response to treatment was similar for children selected by MUAC compared to those selected by WFH
- A high degree of specificity is incredibly important when working with a limited treatment capacity, so whilst we can obviously always reduce the specificity to capture hugely increased numbers, in practice it would be impossible to treat the vast influx in cases, thus we must choose those at highest risk (which we know is determined most effectively using MUAC)
- The Grellety et al. study outlining that children admitted with MUAC alone failed to identify a 1/3rd of all children who died whereas WHZ detected 98% of mortalities, should not be used as a central argument here due to the gross imbalance of “discordant pairs” - of the total sample of 2205 children, only 21 are in the low MUAC high WHZ category (MUAC < 115 and WHZ >-3) and 1486 (70 times more) are in the high MUAC low WHZ category (MUAC > 115 and WHZ < -3), so obviously we'd expect to observe more deaths in the low WFH category.

However, there are still obviously questions remaining that people feel lie unanswered. Maybe it would be helpful for individuals to POST SPECIFIC STUDIES THEY WOULD LIKE TO SEE CONDUCTED, in order to help definitely clarify their position on this issue. It may well be that a useful and relevant study has already been conducted answering your question that you are not aware of, that someone in the forum can bring to your attention. If not, then perhaps this will open up discussion between ourselves re. the possibility of prospective research that would answer any remaining questions – who might be interesting in doing what…..

Answered:

9 years ago

I initially posted this in the "WFH versus MUAC" discussion, but as I think it is also contributing to this discussion...

Dear all,

At this stage, I think it would be helpful to review the hypotheses of André and Mark and the extent to which they are infirmed or confirmed by recently published evidence. I agree that this recent evidence is far from perfect, yet it is good sometimes to see how observations match theory.

So, on the one hand, we have the following hypotheses which have been systematically put forward on this forum:
- Children with a MUAC<115mm have a higher risk of death in the short term than children with WHZ<-3 (which is in fact quite different from the statement that MUAC is a better predictor of mortality than WHZ according to ROC curves see here http://www.ennonline.net/fex/45/consultation for an objective explanation)
- Children with a MUAC<115mm are more in need for SAM treatment (short-term rehabilitation of acute nutritional deficits and appropriate management of clinical complications) than children with WHZ<-3
- Children with WHZ<-3 and MUAC=115mm (WHZonly) are in fact healthy older children with long legs

As expressed in the former consultation of experts mediated by EN-net http://www.ennonline.net/fex/45/consultation it is important to highlight that the evidence supporting these hypotheses is far from being conclusive for everybody.

On the other hand, we have the following recently published evidence:

- Midupper arm circumference and weight-for-length z scores have different associations with body composition: evidence from a cohort of Ethiopian infants.
Grijalva-Eternod CS, Wells JC, Girma T, Kæstel P, Admassu B, Friis H, Andersen GS.
Am J Clin Nutr. 2015 Sep;102(3):593-9. doi: 10.3945/ajcn.114.106419. Epub 2015 Jul 29.

- Inconsistent diagnosis of acute malnutrition by weight-for-height and mid-upper arm circumference: contributors in 16 cross-sectional surveys from South Sudan, the Philippines, Chad, and Bangladesh.
Roberfroid D, Huybregts L, Lachat C, Vrijens F, Kolsteren P, Guesdon B.
Nutr J. 2015 Aug 25;14(1):86. doi: 10.1186/s12937-015-0074-4.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4547414/
This one had been wrongly quoted by Mark, in another thread, as being based on self-selected samples of children: on the contrary, it is based on cross sectional data gathered in representative samples of children

- Comparison of weight-for-height and mid-upper arm circumference (MUAC) in a therapeutic feeding programme in South Sudan: is MUAC alone a sufficient criterion for admission of children at high risk of mortality?
Grellety E, Krause LK, Shams Eldin M, Porten K, Isanaka S.
Public Health Nutr. 2015 Oct;18(14):2575-81. doi: 10.1017/S1368980015000737. Epub 2015 Mar 25.

- Comparison of Clinical Characteristics and Treatment Outcomes of Children Selected for Treatment of Severe Acute Malnutrition Using Mid Upper Arm Circumference and/or Weight-for-Height Z-Score.
Isanaka S, Guesdon B, Labar AS, Hanson K, Langendorf C, Grais RF.
PLoS One. 2015 Sep 16;10(9):e0137606. doi: 10.1371/journal.pone.0137606. eCollection 2015.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4574398/

All these works challenge the aforementioned hypotheses and rather support the alternative hypotheses:
- MUAC<115mm is primarily an indicator of growth retardation in young children, rather than an indicator of acute nutritional needs (contrarily to WHZ)
- MUAC<115mm overdiagnose SAM in young stunted children and underdiagnose SAM in older children
- Children with WHZ<-3 and MUAC=115mm (WHZonly) are at similar high risk of death compared to children with MUAC<115mm, and they respond at least as well to treatment
- Among children with MUAC<115mm, those presenting with WHZ<-3 are the most at risk of immediate death, while those with WHZ>=-3 have more chronic vulnerability profiles.

Further investigations are required and are coming. In the meanwhile, it would be good to stay a bit cautious and to keep in mind both types of hypotheses.

Finally, I would like to say that, although I fully agree with the importance of the feasibility argument for SAM management programmes (especially the difficulty to detect and refer low WHZ children), feasibility is a context and time-specific concept which should not interfere with the need for a deep understanding of the needs for this type of programme.

Benjamin

Benjamin Guesdon

Answered:

9 years ago

Very interesting and confusing debate for field managers. Let me share all of you some findings from field which might be helpful to understand what’s happening in field:
Regarding MUAC indicator: From more than thousands (1400) SAM children admitted by MUAC only (<115m) in treatment program we have around 77% children less than 18months while 95% of them were less than 2 years. In addition, around 65% were female. I had quite similar finding from other programs. Now given the simplicity, eased process to detect cases by MUAC my question is -
- Does it indicate that MUAC particularly tends to identify significantly higher number of younger children and females??? This doesn’t support the fact that MUAC is independent of age and sex sensitivity??
- Colleagues across the globe can share their experiences on this aspect as well. If this is the case in many programs across the globe which means that there is need to review again what was once said independent of age & sex sensitivity!!
To Mark and Andre:
“MUAC < 115 mm and WHZ < -3 23%
MUAC < 115 and WHZ >-3 39%
MUAC > 115 and WHZ < -3 38%
One could easily increase the MUAC to make it more inclusive, increasing the number of high risk children detected, i.e. increasing the sensitivity of screening, without going beyond the patient numbers that you would get by also including all children with WFH < -3”
On the above finding: I believe what you presented is from representative anthropometric cross sectional data (as you mentioned). This usually is age representative (across categories); sex representative and so on due to randomness maintained at sampling stage. This means the proportions are calculated based on representative sample (6-59m) which are equally representative for age, sex and so on…..
- Now make a note: How comes we expect similar proportion as mentioned above from a therapeutic program (MUAC only admissions) that significantly excludes older children (>24m to 59m) as well as female children affecting the age and sex category proportions in sample (the program admitted SAM children)?
- As identified by the authors in the paper http://www.ncbi.nlm.nih.gov/pubmed/?term=Grellety%20E%5BAuthor%5D&cauthor=true&cauthor_uid=25805273
MAUC identifies most likely female and younger children is matches with the finding that I shared as well. Now if similar findings (significantly high number of younger children and girl children) are coming from other programs across countries; we have to review the MUAC sensitivity for age and sex differences again before we rely on MUAC. In addition, we can also consider to investigate why significantly high number of younger children are detected by MUAC <115mm compared to older groups within 59 months as well as female in program setting? This will help enriching our knowledge.
- Again as proposed by Mark and Andre, even if we increase the MUAC cut-offs to identify more children WHZ<-3SD (with elevated risk 11times than normal child http://files.ennonline.net/attachments/1862/WAST_140714.pdf ) question remains “Will that be independent of age and sex sensitivity? Will that also include older children who have severe acute malnutrition (WHZ<-3SD) for their recovery?
Finally, for me, I understood that each expert in the forum is supporting either MUAC <115m only or both nor WHZ<-3SD for programming with logic of simplicity, death predictor (with old evidence) risk bla….bla….
But it was interesting to note that nobody provided insights on which children are actually wasted? What does it mean by the term severely wasted (WHZ<3SD or MUAC) in terms of consequences, not only death but other losses? Does it worth treating SAM children except saving lives i.e is there any other potential benefits from the treatment in mental development/intelligence/sustainable physical growth?

I felt like we are more focussing on convenience and simplicity ignoring the real need while we should start talking about how can we reach those who actually are in need for treatment.

I hope experts from the forum will come with their knowledge and expertise to help understand these questions I have at this moment.

Main M. Chowdhury

Answered:

9 years ago

Dear All,
small correction in what i mentioned to mark and Andre:

Now make a note: How comes we expect similar proportion as mentioned above from a therapeutic program (MUAC only admissions) that significantly excludes older children (>24m to 59m) as well as male (mistakenly wrote female) children affecting the age and sex category proportions in sample (the program admitted SAM children)?

Main M. Chowdhury

Answered:

9 years ago

Benjamin,

I find your mail rather confusing, with a presentation of my ideas and Mark’s of your own which I don’t fully recognise as mine. I invite those who want to know my position to read my posts and my own papers and not to rely on second hand comments.

Apparently, you missed an episode. See my previous posts. The Grellety et al paper (1) that you quote in favour of using WFH is based on a sample from which nearly all children with a MUAC < 115 mm and WFH >-3 were excluded. This results in a sample with nearly all children having a WFH <-3. This explains the artificially high proportion of deaths in children with WFH <-3 compared to MUAC < 115 mm. This study based on a highly truncated sample not at all representative of what you see in the community cannot be used to make any statement in favour of adding WFH when selecting children for treatment.

Also, please note that the Grellety et al. paper (and none of the others you quote) does not contribute in any way to discuss the relevance of slightly increasing MUAC to increase its sensitivity, the most appropriate answer to the concern that MUAC < 115 mm could be too restrictive.

Apparently, you missed also that this low proportion of MUAC<115 mm only children in this sample resulted from an attempt to have more “truly malnourished” children, ie with a low WFH by eliminating all young small children. These excluded children have a high risk of death and were denied treatment in the described programme. This presumably resulted in an excess of preventable deaths in the target population. I will now on use the data presented in this paper to argue that excessive confidence in WFH when running programmes can lead to excess deaths.

1 - Grellety E, Krause LK, Shams Eldin M, Porten K, Isanaka S.Comparison of weight-for-height and mid-upper arm circumference (MUAC) in a therapeutic feeding programme in South Sudan: is MUAC alone a sufficient criterion for admission of children at high risk of mortality? Public Health Nutr. 2015 Oct;18(14):2575-81.

André Briend
Technical Expert

Answered:

9 years ago

We keep coming back to tangentially relevant or misleading evidence:

Givjalva-Eternod et al. (2015) - Interesting but not, I think, directly relevant as the "outcome" measure is of body composition (not mortality). The finding of this paper are at odds with other papers that address this issue. Further work is probably needed although I am not sure if it will be relevant to CMAM programming.

Roberfroid et al. (2015) - Showing that MUAC and WHZ select different children is exactly the point. WHZ perform badly at what we need it to do. MUAC performs better that WHZ at what we need it to do. If MUAC and WHZ selected the same children then MUAC and WHZ would perform equally well as what we need then to do. I avocate for the use of MUAC exactly because because it is different from WHZ (which does very badly at what we need it to do). Please point me to the post where I misrepresent the Roberfroid et al. (2015) paper. I will check and, if needed, write a correcting note.

Grellety et al. (2015) - This has been discussed at length above. This is not appropriate or useful evidence.

Isanaka et al. (2015) - Here we have evidence that children with low MUAC respond to treatment. This is supports using MUAC for admission. We already knew this. The article does not address the issue of mortality risk in untreated cohorts which is what we need to decide whether the discordant MUAC-/WHZ+ children need the full CMAM protocol or could be treated in (e.g.) TSFP type programs. Clinical studies miss the point somewhat (see above re Grelley et  al. (2015)).

It does seem that we need more evidence (although I fear that it will be ignored by those with a "dogmatic attitude in favour of low WFH children"). What you have presented above is not the evidence we need. At best these articles present tangentially relevant evidence. Grellety el al. (2015) is so inappropriate and biased as to be misleading. Your "Further investigations ... " suggest more of the same pseudo-evidence.

I am not sure where the evidence for some of the statements about MUAC and WHZ comes from. We know from the CTC research program that (e.g.) low MUAC kids in SFP die at five or six times the the rate as the same kids in OTP. This was a key piece of evidence for allowing MUAC to be used in OTP programs. I cannot understand the logic behind classifying the identification and admission of children who need and can benefit from the program as over-diagnosis. This is the sort of "logic" that gives rise to the sort of programming described in Grellety et al. (2015).

Please ... rather than keep producing and flaunting tangentially relevant or misleading evidence why not start collecting so useful and appropriate evidence?

Mark Myatt
Technical Expert

Answered:

9 years ago

Sorry ... see here for a discussion of the Grellety et al. (2015) study.

Mark Myatt
Technical Expert

Answered:

9 years ago

Dear MA Chowdhury,

You are concerned that MUAC selects preferentially too many young children. At this stage, please note that the main argument in favour of MUAC is its ability to select high risk children. So the question you ask should be translated into:

Should we correct MUAC for age (and sex) to select children with a high risk of death?

This issue was examined for the first time in a short paper from R Bairagi published ion 1982 who showed that the ROC curves of MUAC corrected and uncorrected for age were nearly identical. I re-examined this issue in my first paper on MUAC in 1986 using age as a continuous variable and also found that adding age (and height) in logistic models did not improve the assessment of the risk of death.

These results were then forgotten, and a similar study was published in 2012 by a Danish group who were not aware of our results. And found the same thing. Correcting MUAC for age or sex (with the then just published WHO growth standards for MUAC) did not improve the assessment of the risk of death. We can describe this as an example of scientific amnesia whereby the same discovery is made several times independently by different groups which ignore each other.

The bias towards younger children makes sense as well from the nutritional point of view (see Briend et al, 2015). When energy and nutrient intake is inadequate, children leave from their fat and muscles. Muscle seems critical for survival in case of infection. And in relation to body weight, young children have a low muscle mass and are presumably more vulnerable.

This increased vulnerability of young children may also explain the poor performance of WFH who is an index based on deviation from a standard, ie a variable obtained from a statistical analysis without any connection to function or pathophysiology.

Measuring muscle mass is nearly impossible in young children, and I am not aware of a paper showing how it grows in normal children. Avaialbe data come from a few post mortem studies. The paper from Ethiopia quoted in Benjamin’s post measured lean body mass, which is completely different and does not have the same nutritional meaning. Its interpretation is difficult and the relevance of this paper for this discussion very low.

Bairagi, R., 1981. On validity of some anthropometric indicators as predictors of mortality. Am. J. Clin. Nutr. 34, 2592–2594.

Briend, A., Zimicki, S., 1986. Validation of arm circumference as an indicator of risk of death in one to four year old children. Nutr. Res. 6, 249–261. doi:10.1016/S0271-5317(86)80129-4

Briend A, Khara T, Dolan C. Wasting and stunting--similarities and differences: policy and programmatic implications. Food Nutr Bull. 2015 Mar;36(1 Suppl):S15-23.

Grijalva-Eternod CS, Wells JC, Girma T, Kæstel P, Admassu B, Friis H, Andersen GS.
Midupper arm circumference and weight-for-length z scores have different associations with body composition: evidence from a cohort of Ethiopian infants.
Am J Clin Nutr. 2015 Sep;102(3):593-9. doi: 10.3945/ajcn.114.106419. Epub 2015 Jul 29.

J Rasmussen, A Andersen, A B Fisker, H Ravn, M Sodemann, A Rodrigues, C S Benn and P Aaby. Mid-upper-arm-circumference and mid-upper-arm circumference z-score: the best predictor of mortality? European Journal of Clinical Nutrition 66, 998-1003 (September 2012)

André Briend
Technical Expert

Answered:

9 years ago

Dear MAChoudhry,

Thank your for your thoughtful post.

The issue of age-independence and MUAC does cause confusion. We use MUAC because if is a good predictor of mortality that can be averted with appropriate nutritional and clinical support. The age-independence of MUAC is assessed with regard to perfromance at identifying these children. If you see MUAC selecting a lot of young male children it is because these children are at high mortality risk. You'l also see MUAC pick up the young stunted children. This is also because these children are at high mortality risk. We know that these children can be treated successfully with the CTC/CMAM protocol. Follow-up studies show good post-discharge survival (often as good or better than never-SAM children).

A MUAC-only program does not "exclude" older children. It will admit older children with low MUAC (who will be at high risk of death and can be treats successfully). It does exclude older children who are at lesser mortality risk. See above for a critique of the program reported in Grelletty et al. (2015). This program decided to exclude young children who were both stunted and wasted and at high mortality risk.

WRT increasing MUAC thesholds ... Yes. This is a better approach than including low WHZ but high MUAC children. Note that we have already done this once (from 110 mm to 115 mm) around 2009. I think this is a far better option than introducing or retaining WHZ. I think a key questions is at what MUAC threshold can we safely replace high intensity care (i.e. OTP) with lower intensity care (w.g. TSFP). At present we have this (almost everywhere at 115 mm). This may be the right threshold. This is (IMO) a useful avenue for further research now that we have good TSFP products.

The proportions were from 552 SMART surveys from 48 countries. These are not perfectly representative but very few surveys are perfectly representative. I think the differences between the figures from the 552 surveys and the Grellety et al. (2015) study are so large as to rule that study out as useful and appropriate evidence. Clinic base studies are of little help with these questions.

We expect MUAC-only programs to better reflect proportions in the population because they tend to have higher coverage due, in large part, to the simplicity and low cost of achieving high spatial and temporal coverage of case-finding activities. I think it is possible for a WHZ program to achieve high coverage but it will be a very expensive program with poor targeting of resources. I have done many coverage assessments and a consistent finding is that WHZ (for a number of reasons)( damages program coverage.

I am not supporting MUAC just because it better targets resources at those in need. It also enables better coverage so that program treat more children at high risk. I think appropriate targeting, high coverage, and good programmatic efficacy are what make for effective programming. I fear that this is missed in much of the MUAC vs. WHZ discussions.

WRT "which children are actually wasted?" ... I don't think I really care much about this. Some people (mostly in then emergency and development nutrition field) will only define wasting as low WHZ. In a clinical context wasting is often defined as loss of peripheral muscle and fat mass (which is low MUAC). My main focus is, however, on child survival so I want an indicator that is a good predictor of mortality that can be averted with appropriate nutritional and clinical support. I suppose that if I were interested in treating children with high body surface area to mass ratios compared to a specially selected reference population then I would push for us to be using WHZ.

WRT additional benefits over survival. That may be the case but any model of hierarchy of needs will have "being alive" at the base of the pyramid. To be blunt ... dead children never grow up and never grow up to be great composers. I see CMAM as primarily a child-survival program and this guised my choices.

I hope this helps.

Mark Myatt
Technical Expert

Answered:

9 years ago

Dear Mark,

You wrote: "I am not sure where the evidence for some of the statements about MUAC and WHZ comes from."

These hypotheses are in my opinion quite well supported by the papers I quoted, as well as by the evidence reviewed in the En-net mediated review, and by Roberfroid et al. for WHO. They also cope quite well with the evidence (not talking here about the comments) you usually present. The reverse is not true: your usual hypotheses are challenge by the recent evidence.

Indeed :
- Knowing that mortality risk decreases with age, a parameter like MUAC, which is strongly related to age, and which is also strongly related to stunting, can be expected to be a good predictor of mortality. It does not need to be an indicator of acute nutritional needs to display this characteristic.
- Young and stunted children without acute nutritional needs, as would be children misdiagnosed as SAM by MUAC, can be expected to display some weight or MUAC gains, especially when treated with high caloric foods. You can even call this recovery if weight or MUAC gain is the only recovery criteria you are interested in measuring.
- However, young and stunted children without acute nutritional needs can hardly achieve the short term rates of weight gain demonstrated by children with acute nutritional needs.

Mark, with the data you have in hands, can you tell us how weight gains of MUAC only children in the short term, let’s say at 2 weeks, compare with weight gains in the two other SAM categories (i.e children with both MUAC<115mm and WHZ<-3; and children with MUACabove115mm and WHZ<-3)?
I am sure you will be interested in the observation made on this point by Isanaka et al.

It is true however that the hypothesis that MUAC-only children are rather chronic than acute could be challenged by the observation of a high immediate mortality risk in these children. Published evidence of this is however not there. I only retrieved a citation of a “natural experiment” observing mortality in children with MUAC<110mm and height below 75cm and WHZ above 70%of the mean (NCHS) in one of your publications, Mark (Myatt 2006). Can you have a look at your files and tell us how many of these children where MUAC<115mm and WHZabove-3, how many were MUAC<115mm and WHZ<-3, and what was their mortality rate?

That would be definitely an interesting piece of information.

Benjamin

Benjamin Guesdon

Answered:

9 years ago

Benjamin

I am not sure that the evidence you present supports any of these hypotheses. The clinical data is (IMO) not very relevant and the Robertfroid et al. (2015) review was highly selective in the evidence presented to the extent that borders (IMO) on fraud. This "evidence" challenges little because it does not present useful and appropriate evidence (see the discussion in this thread). I think we may, in fact, be talking about two different things. Your questions may be very different from mine. Your evidence does not address my questions.

Young and stunted children without acute nutritional needs would not be picked up by MUAC as you suggest. The children that would be picked up would by young, stunted, and wasted. These children have multiple nutritional deficits and are at heightened mortality risk. When we recruit these children into OTP programs they exhibit rapid gains in both weight and MUAC usually following a typical growth curve (i.e. very rapid gains in the first few weeks slowing and approaching an asymptote). When we don't recruit them into OTP and put them into SFP they do not do well (i.e. they die at a much greater rate in SFP than in OTP). This is presented in Myatt et al. (2006). That paper used the case-definitions of the time. It is not a properly designed study (as is usual with natural experiments) but the finding that small, young, low MUAC kids benefit from therapeutic feeding is clear. The practice, as in the program reported bt Grellety et a. (2015), of excluding these children is dangerous and likely to lead to avoidable deaths.

BTW : I cannot look at the natural experiment data and apply the new MUAC case-definition as the study population was children with MUAC < 110 mm. I can confirm that all had a WHZ > 70% (NCHS). The mortality rates (cumulative incidence) were:

In OTP : 0% (no deaths observed in 40 cases) In SFP : 14.8% (8 deaths observed in 54 cases)


The 95% CI on the risk difference was 3.15% to 26.47% (i.e. putting these kids in SFP was clearly a bad idea).

Note how times change. Ten years ago the discordancy was MUAC+/WHZ-. A small study ensured that these kids got what they needed (although the height bar, as applied in Grellety et al. (2015), has undermined this by renewed exclusion of these children without supporting evidence).

We could do a similar (properly designed) trial ... put the MUAC-/WHZ+ kids into SFP and see what happens to them. We'd want to have close monitoring. The Bangladesh trial suggest that they will do well in SFP. I think this is the best way to be sure that our programs deliver the appropriate level of care to these children. I'd be happy to work on such a trial in any capacity.

I have access to a great deal of data. Some is my own data but much has been given / loaned to me for specific analyses. I am sure that I can obtain permissions to use or share much of this data for different analyses. You will understand that I cannot do this without permission from the data owners. I think we should start by working out what our research questions on this topic should be (you seem to have a very different set of questions to me but I amy have several blind spots). We can then see what can be answered by data in hand (and try to do that) and what will need new data. I am sceptical that clinical case-series will be useful. I think that a cohort study looking at what happens to the MUAC-/WHZ+ kids with low intensity treatment might be useful. I do not have data on that.

Mark Myatt
Technical Expert

Answered:

9 years ago

I have started a thread here.

I hope that we can come together there to work out what we need to do to move forward with an informed debate on issues around MUAC-only programming (a wider topic than has been debated here) and the appropriate treatment of children with MUAC > 115 mm and WHZ < -3.

See you there!

Mark Myatt
Technical Expert

Answered:

9 years ago

Dear all,

When I said that it was good sometimes to see how observations match theory, I never meant that it would be a pleasant exercise for everybody. There is no point however in leaving the ground, losing tempers and insulting people engaged in providing more evidence, asking questions, putting forward existing and alternative hypotheses, or simply referring to balanced and collective examination of the scientific literature.

I will now go back to the scientific discussion.

André, you wrote: “MUAC is better predictor of death than WFH”
First, according to the past cohorts and their ROC curves, even age alone would be performing better than WHZ: this does not mean that all children under 2 have acute nutritional needs and should be treated for SAM. Second, this statement does not mean that children with MUAC<115mm have a higher mortality risk than children with WHZ<-3, does it? In which of your publications (or comments) have you shown this? Here I would have missed something.

Mark and André, you wrote: children with MUAC<115mm “exhibit rapid gains in both weight and MUAC usually following a typical growth curve (i.e. very rapid gains in the first few weeks slowing and approaching an asymptote)” and “children with low MUAC respond to treatment and have rapid weight gain”
In fact, it seems that not all children with MUAC<115mm exhibit this type of growth curve, only the ones presenting with both a MUAC<115mm and WHZ<-3 (and the WHZonly category as well). See the paper by Isanaka et al 2015: initial response to treatment in terms of weight gain is much lower in MUAConly SAM children than in the two other SAM categories (children with both criteria, and WHZonly children). This was also highlighted in the review by Roberfroid et al for WHO in 2013. This is also confirmed by many field observations.

Mark, you wrote: “When we don’t recruit them into OTP and put them into SFP they do not do well”, thereby referring to the “natural experiment” you mention in the 2006 paper.
Again, among these children with excess of mortality risk in SFP, what was the proportion of children with both MUAC<115mm and WHZ<-3, and what was the proportion of children with only MUAC<115mm? That would be interesting and useful information for the current discussion.

To conclude, I will not adopt a dogmatic attitude and extrapolate beyond the observations to draw high-impact recommendations restricting the target of SAM management programmes to one or the other of the criteria. I will rather go back to work, and try with my colleagues to provide the evidence we are lacking now.

Benjamin Guesdon

Answered:

9 years ago

We seem to have moved away from legitimate concerns about the discordant (i.e. MUAC - / WHZ+) cases towards a hand-waving attempt at justifying for denial of treatment to young and small children with low MUAC at very high risk of death if left untreated.

Returning to the issue of discordant (i.e. MUAC - / WHZ+) cases ...

I looked again at Figure 1 and Table 2 in Grellety et al. (2015). I worry that the analysis here (IMO) neglects the denominator.

The table in Figure 1 shows:

Cumulative incidence of death = 27 / 719 = 3.76% (95% CI = 2.49%; 5.42%) in MUAC + Cumulative incidence of death = 13 / 1486 = 0.87% (95% CI = 0.47%; 1.49%) in MUAC - / WHZ +


The RR is 4.29 (95% CI = 2.23; 8.27).

It is clear that the mortality risk in the MUAC + group is considerable higher than in the MUAC - / WHZ + group.

We could take a person-days at risk / incidence density approach (data from Figure 1 and Table 2):

MUAC 27 deaths per 719 persons per 51.57 days (27 / 51.57) deaths per 719 persons per day (27 / 51.57) * (10000 / 719) per 10000 per day 7.28 / 10000 / day (95% CI = 4.81 to 10.29 / 10000 / day) MUAC - / WHZ + 13 deaths / 1486 persons / 50.82 days (13 / 50.82) / 1486 persons / day (13 / 50.82) * (10000 / 1486) / 10000 / day 1.72 / 10000 / day (95% CI = 0.92 to 2.78 / 10000 / day)


The IRR is 4.33 (95% CI = 2.18; 8.20). This is essentially the same analysis as above as there was little difference in terms of length of stay between the two groups.

Someone should check my calculations.

We cannot generalise much from this sample or similar samples for many reasons (see the discussions above) but in this program the MUAC + group were at very much higher mortality risk than the MUAC - / WHZ +. Since the program excluded many young and stunted and low MUAC kids using an (IMO) unwarranted height bar we can expect the observed c. 4 fold increase in risk to be an underestimate.

I did the analysis above because I was interested to see mortality rates in the two groups.

Those who promote the continued use of WHZ in CMAM programs are concerned about the 1.72 / 10,000 / day mortality rate in the MUAC - / WHZ + group. That is an elevated (i.e. above acceptable) mortality rate if observed in the general population. We are not, however, looking at a general population ... 0.87% mortality in an OTP patient group is exceptionally low. The 95% CI suggests that what we see in this this group in this program is not statistically significantly different from 1 / 10,0000 / day.

I think we should be careful with this evidence and not be quick to dismiss concerns about here being real need in the MUAC - / WHZ + children. I think we can conclude that there is need but that need may be different. The MUAC - / WHZ + may not require the high intensity treatment provided by OTP and do very well with a lower intensity therapy. I think that we need to concentrate on this question.

Also looking at Figure 1 ... in MUAC in the MUAC - / WHZ + tends to be low (most are below 125 mm). This suggest (to me) that MUAC only programming with a MUAC < 125 mm admission with two clinical pathways (i.e. MUAC < 115 mm get OTP, MUAC between 115 and 125 mm get something less intensive) would (1) address the concerns of WHZ proponents, (2) retain the advantages of MUAC only programming, and (3) contol costs and crowding (if designed properly).

Mark Myatt
Technical Expert

Answered:

9 years ago

Benjamin,

When you assess growth of low MUAC children receiving RUTF, the comparison group should be children not receiving treatment. Comparison with low WFH children also receiving RUTF is not really relevant. Also, note that measuring weight gain in relation to initial WFH will show an artificially high effect, as WFH is strongly correlated with initial weight which is used to calculate weight gain. You can play with computer generated random numbers to see this bias at work.

Risk of deaths and sensitivity of different indicators to assess the risk of deaths should be compared at similar specificity level. Adding children with a WFH < -3 to a MUAC <115 mm only programme will result in a 60% increase of patient numbers. Mark just did a quick calculation on the 552 surveys and found that this increase in patient number is roughly equivalent to what you would get by increasing MUAC cut off around 120 mm. Number of deaths observed in children with WFH <-3 should be compared with number of deaths of children less than 120 mm MUAC if we want to compare screening schemes selecting about the same number of children.

I think you will have a hard time to convince any one with a few notions of epidemiology that community based studies represent lower quality evidence compared to hospital based studies when discussing screening at the population level. And this is what you do in the WHO document and again repeatedly in this forum. And you and Roberforid in his last 2015 paper put forward the Grellety et al study, which is an embarrassment to the humanitarian community as its table shows clearly that it is based on a programme which left the most high risk children untreated. You should stop doing that.

And please kindly stop quoting the 2015 Roberfroid paper to reject MUAC as it does not agree with MUAC. This has been said again and again and is not an accepted argument. Or quote this paper, as I will do, to argue that MUAC selects children who tend to be younger, and more stunted, and hence more at risk compared to low WFH children.

I wonder how useful it is to continue this discussion.

André Briend
Technical Expert

Answered:

9 years ago

Dear Mark and André,

I was not expecting that you would answer my previous questions and that you would accept to consider the hypotheses I was putting forward.

You have been pushing so far for MUAC-only recommendations, for so long... Contradictory hypotheses, even when supported by facts and published evidence, are obviously frightening you.

I hope however that the people following this forum will give it a new and critical look, and will go by themselves to these papers quoted by me and others, rather than rely on your analysis.

It is more than time for us to switch from eminence-based to evidence-based nutrition.

Benjamin Guesdon

Answered:

9 years ago

See the discussion above. I have engaged with your "evidence" and your "facts" and find them lacking relevance and intellectual rigour.

I reviewed some of the evidence in one of your "key exhibits" again just this morning and posted a message looking at the mortality claims being made.

Come back with some relevant facts and relevant evidence and I will take you seriously.

As for my fear of evidence ... you seem to have missed my post here. I want evidence of direct rather than tangential relevance. Why not join in? I am certain I do not have all the answers. I am also equally certain that you do not have all the answers.

I think it is time for us to stop bickering and move forward on these important issues.

Mark Myatt
Technical Expert

Answered:

9 years ago

Dear all,

I think this discussion has run its course and propose we close it and move on to a dialogue about key pieces of research or evidence that are missing in the debate and would help us move forward.

There is a new thread here where people can engage in that discussion.

Thanks to everyone for their valuable contributions to this discussion.

Best wishes,
Tamsin

Tamsin Walters
Forum Moderator

Answered:

9 years ago

Dear all,

We have been notified that there are others who would still like to contribute to this discussion, so I am reopening it for additional comment.

Best wishes,
Tamsin

Tamsin Walters
Forum Moderator

Answered:

9 years ago

Dear All,

It would be intersecting to share and all you read the "Inconsistent diagnosis of acute malnutrition by weight-for-height and mid-upper arm circumference: contributors in 16 cross-sectional surveys from South Sudan, the Philippines, Chad, and Bangladesh"

As a final the research concludes " MUAC 125 should not be used as a stand-alone criterion of acute malnutrition given its strong association with age, sex and stunting, and its low sensitivity to detect slim children. Having ‘longer legs’ moderately increases the diagnosis of acute malnutrition by WHZ -2 . Prospective studies are urgently needed to elucidate the clinical and physiological outcomes of the various anthropocentric indicators of malnutrition "

What is your view?

Anonymous

Answered:

9 years ago
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