Randomization, masking, and intervention
Randomization occurred at the end of a baseline study visit, using a 1:1 allocation ratio in blocks of 10. A member of the study team invited each household caregiver to select and open a sealed, opaque envelope from a basket containing the child’s group, under the supervision of a study-independent community member who was blinded to group assignment. When the number of available envelopes dropped below three, a new block of 10, which included five from the intervention and five from the control group was added to the basket. The intervention was not blinded to the participants or the staff completing the home visits. However, the staff collecting data related to study outcomes—including anthropometrists, interviewers, phlebotomists, and laboratory professionals—were blinded to group allocation.Families in the intervention group received weekly egg deliveries and were visited twice per week to observe a caregiver feeding the child. Each household in the intervention group was provided with an egg storage basket and directions on food hygiene and handwashing. Suggestions for egg preparation, cooking recipes, and instructions to not share the intervention eggs with other family members were also provided. However, due to the high likelihood of egg-sharing with other household members, families were given an additional seven eggs per week.Households in the control group were also visited twice per week and given messages about food hygiene and handwashing during food preparation but no eggs or other food items. During the trial, control group households received incentive items such as a bucket, hand washing basin, laundry tub, and lidded plastic bin. At the end of the study, they received a food basket containing items like flour, sugar, oil, and 15 eggs, as well as food storage containers and cloth diapers. The total of these incentive items matched the value of the eggs provided to the intervention households.