Dibley 1996.

Study characteristics
Methods	Individually randomised trial conducted in 34 rural villages located on the southern coast of Central Java in Indonesia
Participants	Eligibility: children aged 6–47 months Excluded: children with cerebral palsy, epilepsy, flaccid paralysis, mental retardation, congenital or rheumatic heart disease were permanently excluded; those with weight‐for‐height > 3 standard deviations below the WHO growth reference mean or acute xerophthalmia were excluded for 1 cycle and treated with high‐dose vitamin A and then included Sample: 1405 children; 50.9% boys
Interventions	Experimental group: vitamin A 206,000 IU in form of retinyl ester + vitamin E 37 IU for children aged > 12 months or 103,000 IU in form of retinyl ester + vitamin E 17 IU for children aged < 12 months of age Control group: placebo containing vitamin E 17 IU or 37 IU according to the age of the participant Study duration: intervention given every 4 months for 24 months Mean of 89% of the children received a treatment (vitamin A or placebo)
Outcomes	All‐cause mortality, incidence of diarrhoea and respiratory disease, mean vitamin A serum level, proportion of vitamin A deficient, growth
Notes	Baseline demographic, clinical, and nutritional characteristics of the participants were the same, and the groups remained balanced at the start of each of the other 5 cycles. Children were visited every other day for 6 cycles. The longest recall period allowed was 4 days. Observed child‐days of ALRI of the vitamin A group was 280,186 and the control group was 273,630. According to WHO, Indonesia is a country with a high child mortality rate (i.e. > 40/1000).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization of the treatments was done with a 1:1 allocation ratio in blocks of eight, based on a table of random permutations of integers". Comment: likely to be adequate.
Allocation concealment (selection bias)	Low risk	Quote: "All investigators, field and laboratory staff, and participants were masked to the treatment code". Quote: "The capsules were packaged in opaque blister packs with a unique treatment code".
Blinding (performance bias and detection bias) Blinding of participants	Low risk	Quote: "The oily contents of the vitamin A and placebo capsules were of similar taste and colour".
Blinding (performance bias and detection bias) Blinding of provider	Low risk	Quote: "All investigators, field and laboratory staff, and participants were masked to the treatment code". Comment: adequate allocation concealment and the identical presentation of placebo and vitamin A should have prevented providers becoming unblinded to treatment group assignment. Low risk of performance bias.
Blinding (performance bias and detection bias) Blinding of outcome assessor	Low risk	Quote: "All investigators, field and laboratory staff, and participants were masked to the treatment code". Comment: adequate allocation concealment and the identical presentation of placebo and vitamin A should have prevented outcome assessors becoming unblinded to treatment group assignment.
Incomplete outcome data (attrition bias)	Low risk	Comment: complete details of those excluded and lost to follow‐up with reason were described. There was a low and balanced number of withdrawals between groups. The analytical method account for the time on treatment (i.e. follow‐up time for each cycle), and this may have been adequate.
Selective reporting (reporting bias)	Low risk	Comment: lack of trial protocol hindered full assessment of this item. However, data on outcomes of relevance to the review were reported.
Other bias	Low risk	Comment: study appeared free of other bias.