Effect of short-term RUTF distribution on children in Niger

Summary of published research¹

Mothers and children arriving for their monthly surveillance visits, as part of the trial

Researchers from the Harvard School of Public Health have recently published the findings of a study to evaluate the effect of a 3-month distribution of Ready to Use Therapeutic Food (RUTF) on the nutritional status, mortality and morbidity of children aged 6 to 60 months in Niger.

The primary hypotheses were that village-level supplementation with RUTF in the months preceding the annual harvest would prevent declines in individual weight-for-height and reduce the incidence of wasting in children aged 6-60 months over a period of 8 months. Because RUTF may have additional health effects, the intervention effect on individual height-for-age, stunting, mortality and morbidity from malaria, diarrhoea and respiratory tract infection were also examined.

The study involved a cluster randomised trial of 12 villages in Maradi, Niger. Six villages were randomised to intervention and six villages to no intervention. All children in the study villages aged 6 to 60 months were eligible for recruitment. Maradi, which is located in the south-central part of the country bordering Nigeria, has some of the highest rates of malnutrition in the country. Prevalence of moderate wasting in Maradi was estimated to be 11.6% between January and May 2006.

Children with weight-for-height 80% or more of the National Centre for Health Statistics (NCHS) reference median in the six intervention villages received a monthly distribution of 1 packet per day of RUTF (92g [500kcal/d]) over 3 months from August to October 2006. Children in the six non-intervention villages received no preventive supplementation. Active surveillance for conditions requiring medical or nutritional treatment was conducted monthly in all 12 study villages, from August 2006 to March 2007.

The main measures of outcome of the study were changes in weight-for-height z score (WHZ) according to the WHO Growth Standards and incidence of wasting (WHZ < -2) over eight months of follow-up.

The main findings of the study were as follows.

The number of children with height and weight measurements in August, October, December 2006 and February 2007 was 3166, 3110, 2936 and 3026 respectively. The WHZ difference between the intervention and non-intervention groups was - 0.10z (95% confidence interval [CI], -0.23 to 0.03) at baseline and 0.12z (95% confidence interval 0.02 to 0.21) after 8 months of follow-up. The adjusted effect of the intervention on WHZ from baseline to the end of follow-up was thus 0.22z (95% CI, 0.13 to 0.30). The absolute rate of wasting and severe wasting, respectively, was 0.17 events per child-year (140 events/841 child-years) and 0.03 events per child-year (29 events/943 child-years) in the intervention villages, compared with 0.26 events per child-year (233 events/895 child-years) and 0.07 events per child-year (71 events/1029 childyears) in the non-intervention villages. The intervention thus resulted in a 36% (95% CI, 17% to 50%; p <0.001) reduction in the incidence of wasting and a 58% (95% CI, 43%-68%; p < 0.001) reduction in the incidence of severe wasting. However, only a small benefit of supplementation appears to be sustained in the months after supplementation ceased. There was also a limited effect of RUTF supplementation on height-for-age z score (HAZ), no increased risk of malaria and reduction in mortality - the mortality rate was 0.007 deaths per child-year (7 deaths/986 childyears) in the intervention villages and 0.016 deaths per child-year (18 deaths/1099 childyears) in the non-intervention villages (adjusted hazard ratio, 0.51; 95% CI, 0.25 to 1.05).

The authors acknowledge several limitations with the study, including a small number of clusters that limited the benefits of randomisation, potential measurement error and inability to measure dietary intakes at recruitment or during the intervention.

The authors conclude that short-term supplementation of non-malnourished children with RUTF reduced the decline in WHZ and the incidence of wasting and severe wasting over 8 months. However, the effectiveness of preventive supplementation with RUTF in other settings may depend on RUTF acceptability, the extent of resale after distribution and the adequacy of the public health and nutrition systems in place. It is also argued that further research is warranted to identify the minimal dose required to achieve an effect and to compare the effect of other formulations of RUTF and locally available diets, which also may be effective in improving nutritional status in children. Information is also needed on the cost-effectiveness and feasibility of large scale RUTF distribution. The relatively high costs of imported RUTF and locally produced RUTF may challenge the effective scaling up of short-term RUTF supplementation.

The authors believe this to be the first population- based study to evaluate the effectiveness of RUTF in the prevention of wasting, although it is asserted that the protective effect of the intervention on WHZ decline and wasting incidence is consistent with the therapeutic use of RUTF in a variety of settings.

¹Isanaka. S et al (2009). Effect of preventive supplementation with Ready-to-use therapeutic food on the nutritional status, mortality and morbidity of children aged 6 to 60 months in Niger: a cluster randomised trial. JAMA. 2009;301 (3): 277-285