Effect of the IST intervention at 9- and 24-months follow-up on educational achievement (spelling and arithmetic) outcomes for younger (class 1) and older (class 5) children.

Results presented (i) for all children with outcome data (unadjusted) and (ii) for those with baseline measurements of each outcome and accounting for age, sex, and stratification effects (adjusted) as the primary pre-specified analysis. N, number of children eligible for follow-up (not withdrawn or deceased). Adjusted: for baseline age, sex, school mean exam score and literacy group (to account for stratification) and baseline measure of the outcome, where available; unadjusted: all children with outcome measures, not adjusted for any baseline or study design characteristics.aMean difference (intervention-control) for scores on spelling and arithmetic are obtained from GEE analysis accounting for school-level clustering.bMean score and SD at follow-up.cThe same class 1 spelling task was given at baseline, 9- and 24-months follow-ups, with different words used for the 24-month follow-up.dSame addition task conducted at 9-months follow-up and at baseline, hence baseline adjustment is for the same task.eThe same class 5 spelling task was given at baseline, 9- and 24-months follow-ups, with different words used for the 24-month follow-up.fSame arithmetic task conducted at baseline, 9- and 24-months follow-ups, with different sums used for the 24-month follow-up.gAddition task conducted at baseline and arithmetic task containing addition, subtraction, multiplication, and division conducted at 24-months follow-up, hence baseline adjustment for different task.