Study Protocol: The Impact of Growth Charts and Nutritional Supplements on Child Growth in Zambia (ZamCharts): A Cluster Randomized Controlled Trial

AbstractBackground:Almost a quarter of children under the age of five in low- and middle-income countries (LMICs) currently experience growth faltering. Early childhood stunting (height/length-for-age z-score < -2) is associated with a range of adverse later life outcomes including reduced cognitive development, poor school achievement and increased probability of living in poverty as adults. Few effective interventions are currently available to address stunting in LMICs.Methods: We will conduct a 2x2 cluster-randomized factorial trial with ~2300 caregiver-child dyads residing in 280 communities (clusters) located in Luapula, Lusaka, and Southern Provinces of Zambia. Clusters will be randomized into four groups each comprising 70 clusters with ~560 caregiver-child dyads: i) a control group ii) a growth charts only group; iii) a small quantity lipid-based nutrient supplements (SQ-LNS) only group; and iv) a growth charts + SQ-LNS group. Families in the growth charts groups (ii and iv) will receive a locally developed poster installed in their home that allows them to compare the height of their children to the World Health Organization’s international growth reference tables. The poster will also include health and nutrition messages for infants and young children in alignment with Ministry of Health recommended practices. Families in the SQ-LNS groups (iii and iv) will be given monthly rations (30 sachets) of SQ-LNS over a period of 18 months. Pediatric anthropometry and a caregiver survey will be conducted at baseline and endline. The primary study outcome is height-for-age z-score and stunting (HAZ < -2) after 18-months of intervention, when children will be between 24 and 36 months of age. Secondary outcomes will be anemia, weight-for-height, weight-for-age and child development. In a subsample we will also assess micronutrient status (Retinol-binding protein (RBP) for Vitamin A deficiency, ferritin for iron deficiency, and hemoglobin for anemia), inflammation (C-reactive protein (CRP), α1-acid glycoprotein (AGP)), biomarkers of environmental enteric dysfunction, the composition of the bacterial community in the gut microbiome and saccadic reaction time (SRT), an eye-tracking measure of neural function.Discussion:This study was designed to assess the impact of growth charts as well as the extent to which early childhood growth faltering can be mitigated through SQ-LNS supplementation in three purposely selected highly diverse areas of Zambia.Trial registration:This study is registered at clinicaltrials.gov as NCT0512042. https://clinicaltrials.gov/ct2/show/NCT05120427