Effect of mass supplementation with RUSF during an anticipated nutritional emergency

Summary of published research¹

A woman and her dauguher receive RUSF distribution in Niger

Location: Niger

What we know already: Ready to Use Supplementary Foods (RUSF) are successfully used in the treatment of MAM.

What this article adds: RUSF distribution and a food protection ration to self-selected children aged 6 to 23 months during an ‘at risk’ period had a positive effect on wasting, anthropometric status and survival. There are study limitations to bear in mind. Contextual factors to determine use of RUSF in preventative strategies are important.

Each year in Niger, the months preceding the harvest (June to October) are associated with increased wasting among children. The region of Maradi, located in the south-central part of the country bordering Nigeria, has some of the highest rates of malnutrition in Niger. From July to October 2010, in collaboration with the Ministry of Health, Médecins Sans Frontières (MSF) and Forsani distributed supplies of Ready to Use Supplementary Food (RUSF) to registered children aged 6 to 23 months living in the districts of Guidam Roumdji and Madarounfa in the region of Maradi. The World Food Programme (WFP) also distributed protection rations to families during this period. A recently published paper reports the findings of a prospective cohort designed to monitor these interventions. The authors present a comparison of the incidence of wasting, anthropometric changes and mortality in children aged 6 to 23 months who participated or did not participate in the monthly distributions over a four month follow-up period. The study protocol was approved by the Comité Consultatif National d’Ethique du Niger, and authorised by the Ministry of Public Health of Niger.

After a community awareness campaign, a mass registration exercise was held in July 2010 to enrol children in the distribution programme. All children 60-80cm in length (aged approximately 6 to 23 months) resident in the districts of Guidam Roumdji and Madarounfa were invited to attend and be registered for the programme. Once registered, children were eligible to receive monthly distributions from July to October of Plumpy’DozH (Nutriset, Malaunay, France).

Monthly distributions of RUSF were made in pots (4 pots = 1 monthly ration per child) at sites located within walking distance from each village. At the time of RUSF distribution, nutrition assistants also screened children in attendance for mid upper arm circumference (MUAC) <115 mm or oedema and referred children to the closest nutritional treatment programme when indicated. The RUSF distribution was sometimes accompanied by WFP’s family protection ration.

To follow the nutritional status of children who were registered in the distribution programme (intervention group) and those who failed to be registered (comparison group), the study team randomly selected twenty villages (ten in each district). A complete list of villages and hamlets in both districts was stratified, first by accessibility (presence of a health centre, market, paved road and modern water point within a radius of 10 km), and second by administrative status (village or hamlet). Villages were randomly selected with probability proportional to population size within the four strata. Two days after registration was closed, exhaustive enrolment was conducted independently by the study teams in each of the 20 cohort villages of all children meeting the inclusion criteria of the MSF/Forsani distribution programme by teams going from house to house within each village. Thus, within the cohorts, there were both children who were registered to receive the distribution and those who were not.

Approximately two weeks after each monthly distribution, trained nutrition assistants, independent of the staff conducting the distributions, carried out anthropometric measurements with the use of standardised methods and calibrated instruments.

During the first and last post-distribution visits, a standardised questionnaire was administered to obtain information on household, maternal and child socio-demographic characteristics. An abridged questionnaire was used at each post-distribution visit to obtain information on the major health events, including both death of the child and the extent of sharing of the RUSF and WFP ration within the household. Moreover, during each visit, the remaining quantities of distributed food were weighed and compared with the rations received.

Children aged 6 to 23 months at baseline in the cohort villages who were registered and participated in at least one of the four monthly distributions (intervention group) and those who did not participate in any of the RUSF distributions were compared (comparison group). The endpoints were wasting (weightfor- length z score (WLZ) <-2 or MUAC <125 mm), severe wasting (WLZ <-3, or MUAC <115 mm), stunting (length-for-age z score (LAZ) <- 2) severe stunting (LAZ <-3) and mortality. Mortality events included all reports for which the cause for absence from surveillance visits was reported to be death, by a family member or the head of village. All data were collected on standardized forms and double entered into EpiData version 2.1 (EpiData Association, Odense, Denmark). Analyses were conducted using STATA version 10 (StataCorp, College Station, TX, USA).

Results

A total of 2,238 children aged 6 to 23 months in 2,127 household were enrolled in the cohort at baseline. None of the children in the cohort communities refused to join the study. Of the children enrolled in the cohort, 1,400 children were registered to participate in the distribution (intervention) and 838 children (comparison) were not registered to receive the supplementary food distribution. The cohort represented 4.3% of the total 6 to 23 month old population of the districts of Guidam Roumdji and Madarounfa.

All children did not receive the same number or type of distributions over the four month follow-up. Although, approximately 51% of households received Corn Soy Blend (CSB) at the first distribution, there were no further distributions of this type. Most families received only one or two distributions of the family rations. Thirteen percent of the intervention group only received RUSF once, 9% twice, 19% three times and 59% received all four distributions. Thus, 78% of the children designated as receiving the interventions (intervention group) received 3 or more distributions.

At baseline, the intervention and comparison groups differed in age and household composition. Children in the intervention group were slightly younger (p =0.004) and lived in households containing more under 5 year old children (p =0.001). There were five (0.3%) children absent at the end of the study and whose outcome was therefore unknown in the intervention group and 35 (4.2%) children in the comparison group.

The number of children with anthropometry measured in July, August, September and October were 1,392, 1,364, 1,328 and 1,221 in the intervention group and 794, 760, 707, and 597 in the comparison group respectively.

Over all distributions, 58% of RUSF was reported to be shared with other younger siblings within the same household. Almost the entire family protection ration (85%) was shared within the same household.

The absolute rate of wasting was 1.59 events per child-year (503 events/3,784 child-months) in the intervention group and 1.78 events per child-year (322 events/2,165 child-months) in the comparison group. The intervention group had a small but higher WLZ change (20.2 vs. 20.3 z; p = 0.006) and less loss of MUAC than the comparison group (22.8 vs. 24.0mm; p = 0.002) comparing pre- to post-final distributions. There was no difference in length gain (2.7 vs. 2.8cm) among groups. Fewer initially non-wasted children developed moderate wasting in the intervention group than the comparison group.

Mortality was lower for children whose households were in the intervention group than those who were not (adjusted HR: 0.55, 95% CI: 0.32 to 0.98). In total, 29 per 1000 children enrolled in the cohort died during the followup period. Of these, no child receiving all four distributions died, five children died who received three distributions, seven children receiving two distributions and six children receiving only one distribution.

Discussion and limitations

RUSFs are formulated to supply all of the essential nutrients, both those required to maintain body function and for normal growth. A deficiency of one or several of the functional nutrients impairs physiological or immunological function without any effect on anthropometric indices. The authors of this study argue that the benefits in terms of mortality, combined with a very modest effect upon weight and MUAC, may potentially have been due to the correction of functional deficiencies, not causally associated with anthropometric deficits, but resulting in functional changes increasing mortality risk. It is noteworthy that many of the deaths were in children that were neither moderately or severely malnourished anthropometrically, and it appeared that this group of not-wasted children benefited most from the RUSF distribution in terms of mortality avoidance. This was unexpected and would indicate that even modest amounts of those nutrients whose deficiency is not associated particularly with wasting could be implicated in the reduction in mortality. This would have major implications for targeting in such situations, and perhaps for the composition of the RUSF supplied.

The authors highlight several important limitations to these results which require discussion. First, children themselves were not randomised to receive the distributions, but were either registered or failed to be registered at the time of the initial mass registration and subsequently observed. It is unclear why some children were not registered initially, possibly caregivers were absent at the time of registration, the benefits of the programme were not adequately explained or advertised, or they felt their child did not need the RUSF on offer. As a result, differences between the intervention group and comparison group could account for the observed reduction in mortality. However, in addition to accounting for differences in the statistical analyses, baseline anthropometry of children was not significantly different between groups. The intervention group had a slightly lower, but not statistically different, mean weight-for length, they came from larger families and were younger. These are recognized risk factors for mortality, thus, the children receiving the distributions were likely to have been at higher risk of death than the comparison group. It is important also to note that the population was under very severe stress with mortality rates when expressed in conventional emergency terms of 1.7/10,000/d for the intervention group and 2.9/10,000/d for the comparison group. As children identified as severely malnourished were admitted to therapeutic programmes, in the absence of the distribution programme, mortality may have been higher. In addition, mortality in the comparison group may be underestimated as five children in the intervention group and 35 in the comparison group were lost to follow-up. If all, or a proportion, of these children were lost to follow-up because of death, the strength of the reduction in mortality with the distribution would increase. Overall, there were fewer deaths among children in the intervention group irrespective of the number of distributions received.

Second, there may be unexplained differences between the intervention and comparison group. One possible hypothesis arising from these results is that families receiving the distributions have children already showing signs of deterioration, as evidenced by the presence of known risk factors at baseline. Families with children who are in better health at the time of registration may choose not to participate, highlighting the potential weakness of programmes with closed enrolment.

Third, it is possible that the severity of the situation was the reason for the extensive sharing of supplement within the family and this in turn led to the modest differences in wasting found.

Fourth, over the four month follow-up, there was no observed effect upon stunting. Review of complementary feeding interventions suggests that the effect of RUSF on linear growth has been inconsistent, with significant improvements achieved only in some settings and the acceleration of length gain may only occur after supplementation has been given for several months.

Fifth, it was not possible to differentiate the effect of the RUSF from the family protection rations, nor was it the aim of the study. However, the distribution of protective rations was inconsistent and almost non-existent during the fourth distribution. This coupled with the known inadequacies of nutrient composition of the family ration to meet the needs of young children contribute to the limited evidence for including RUSF in distributions.

Finally, potential errors in the child’s age at recruitment or measurement errors for the anthropometric variables, despite continual training of field teams, may have reduced or increased the statistical power to detect significant effects.

Conclusions

The authors conclude that the results of this study show that the RUSF distribution with a protection ration for the families had a positive effect on wasting and anthropometric status of children who received the distribution in comparison to those who did not. Importantly, deaths were halved for recipients compared to non- recipients. These results suggest that with similar access to health services, distributions can have a positive impact on child survival. Contextual factors will continue to be important in determining the dose, duration, period and modalities of such preventive intervention based on RUSF. Dietary supplementation with foods specifically formulated for vulnerable populations have become a component of government-run social safety net programmes. In settings of endemic malnutrition and high child mortality, the health impacts of RUSF documented through humanitarian projects may help inform decision making for longer term programming.

¹Grellety E, et al. (2012). Effect of Mass Supplementation with Ready-to-Use Supplementary Food during an Anticipated Nutritional Emergency. PLoS ONE 7(9): e44549.doi:10.1371/ journal.pone.0044549. Full article available at: http://www.plosone.org