Additional analyses
Additional analysis to be conducted include an economic evaluation calculating total average cost, and total average cost per 0.1 standard deviation improvement in the primary outcome. The standard deviation to be estimated by fitting a linear mixed model with cluster-specific random effects to the primary outcome in the control arm of the trial, with the standard deviation estimated via a summation of the between- and within-cluster variances. The included costs will be all costs for running the intervention and any capital costs will be amortized according to the item. It will include all costs that would occur if the trial intervention were continued without the research costs related to a trial. It does not reflect the costs that a government organization would observe if they took over the intervention. It does not include any costs to families.Also, as a result of the COVID-19 lockdowns, additional support was provided to enrolled children and their mothers. Summary data relating to this will be tabulated. Data collected included the number of direct messages sent to children and the response rate to these messages, the number of home-visits received, attendance of mothers in fortnightly meetings to encourage engagement, access to and use of books at local libraries and, access to and use of a tablet providing digital learning.