Agarwal 1995.

Study characteristics
Methods	Cluster‐randomised trial conducted in Uttar Pradesh, India
Participants	Eligibility: children aged < 6 years Excluded: children with xerophthalmia Sample: 16 clusters (subcentres) were randomly selected and divided into 4 subdivisions (4 subcentres in each), with drugs A (vitamin A) and B (placebo) distributed in 2 each randomly. At the end of the study, investigators found that vitamin A was distributed in 3 subdivisions (12 subcentres) and placebo in 1 only (4 subcentres) by mistake. 17,778 children were approached but only 15,247 children were included in the final analysis based on the fact that they received ≥ 1 dose of vitamin A
Interventions	Experimental group: vitamin A 50,000 IU + vitamin E 10 IU for children aged 1–6 months and vitamin A 100,000 IU and vitamin E 20 IU for children aged 7–72 months Control group: placebo Study duration: intervention delivered every 4 months for 12 months
Outcomes	All‐cause and cause‐specific mortality due to diarrhoea, pneumonia, measles, and meningitis
Notes	The trial was conducted in 2 phases. The first phase consisted of 15 months (i.e. 3 months for registration and 12 months for intervention and measurement of relevant outcomes). In the second phase, mortality was measured in a subsample of initially included children, exactly 12 months after termination of first phase. The cause of death was assigned using a verbal autopsy tool. Baseline mortality rates for children < 6 years of age were 27.7 for the intervention group and 23.3 per 1000 for the control group, with significant differences in the 2 groups (P < 0.01). According to WHO, India 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)	Unclear risk	Quote: "Out of the total 43 subcentres, 16 were randomly selected, four subdivisions (4 subcentres in each) were made and drugs A and B distributed in two each randomly". Comment: authors did not specify the method of sequence generation.
Allocation concealment (selection bias)	Unclear risk	Comment: insufficient information to permit judgement.
Blinding (performance bias and detection bias) Blinding of participants	Unclear risk	Comment: insufficient information to permit judgement.
Blinding (performance bias and detection bias) Blinding of provider	Unclear risk	Comment: insufficient information to permit judgement.
Blinding (performance bias and detection bias) Blinding of outcome assessor	Unclear risk	Comment: insufficient information to permit judgement.
Incomplete outcome data (attrition bias)	Unclear risk	Comment: insufficient information to permit judgement.
Selective reporting (reporting bias)	Unclear risk	Comment: insufficient information to permit judgement.
Other bias	Unclear risk	Comment: insufficient information to permit judgement.