Sommer 1986.

Study characteristics
Methods	Cluster‐randomised trial conducted in a rural area of Indonesia
Participants	Eligibility: children aged 0–5 years Excluded: children with active xerophthalmia Sample: 29,236 children from 450 villages (cluster sites) in Java. 50% boys
Interventions	Experimental group: vitamin A 200,000 IU capsules administered twice over the course of the study + vitamin E 40 IU Control group: no treatment (served as a waiting list control) Study duration: 9–13 months
Outcomes	Mortality, diarrhoea, Bitot's spots, night blindness, xerophthalmia
Notes	ICC not reported (CIs from analyses reported to have been adjusted for design effect). TJL back‐calculated an ICC of 0.008307 from effect estimate provided in paper. Vitamin A was not intended to have been distributed to children aged < 12 months, but it would appear that some children aged 0–12 months received the vitamin A capsule. Outcome data were reported on a cohort of 0‐ to 12‐month‐old children.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "From a random start, 450 villages were systematically selected for the study; these were then randomised for capsule distribution after the baseline examination …". Comment: inadequate information provided.
Allocation concealment (selection bias)	Unclear risk	Comment: inadequate information was presented to assess this item in relation to timing of recruitment into the study.
Blinding (performance bias and detection bias) Blinding of participants	Unclear risk	Quote: "The Government of Indonesia would not condone the use of placebos but field‐workers collecting demographic data were unaware that mortality was a research issue". Comment: described as a controlled study, without adequate description of what the control group received.
Blinding (performance bias and detection bias) Blinding of provider	Unclear risk	Quote: "The Government of Indonesia would not condone the use of placebos but field‐workers collecting demographic data were unaware that mortality was a research issue". Comment: described as a controlled study, without adequate description of what the control group received.
Blinding (performance bias and detection bias) Blinding of outcome assessor	Unclear risk	Quote: "The Government of Indonesia would not condone the use of placebos but field‐workers collecting demographic data were unaware that mortality was a research issue". Comment: described as a controlled study, without adequate description of what the control group received.
Incomplete outcome data (attrition bias)	Unclear risk	Quote: "Follow‐up information was available on 89% of the programme children and 88.4% of the controls". Comment: authors indicated percentage remaining per group at follow‐up, but nothing more detailed.
Selective reporting (reporting bias)	Unclear risk	Comment: trial protocol not available.
Other bias	Unclear risk	Comment: insufficient information to permit judgement.