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To the Editor: Ms Isanaka and colleagues¹ conducted a cluster randomized trial to evaluate the effect of ready-to-use therapeutic foods on various measures of nutritional status, morbidity, and mortality in children in Niger. The cluster randomized trial design is a very useful one for this setting because of logistical constraints. However, such a design leads to analytic complications.

There are 2 levels of correlation in the study that need to be accounted for in the analysis. The first is that the children were clustered within households. This is shown in Figure 1 of the article, which indicates 1671 children from 647 households in the intervention group and 1862 children from 760 households in the control group. This leads to use of mixed-effects models in which correlation is accounted for at the village, household, and individual levels.

However, the survival analyses are more problematic in this setting. The authors employed a . . . [Full Text of this Article]

Debashis Ghosh, PhD
ghoshd@psu.edu
Department of Statistics
Penn State University
University Park, Pennsylvania

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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 Randomized Trial
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