Brooks 2005.

Methods	RCT in which random assignment to zinc or placebo was done with permuted blocks of variable length between 2 and 8. Placebo was designed to be identical to the zinc syrup in colour, odour, and taste. The study was conducted at Kamalapur, southeastern Dhaka, Bangladesh. The medical officer diagnosed pneumonia if crepitations were heard on inspiration with a respiratory rate greater than 50 breaths per minute; severe pneumonia was diagnosed if there was also chest indrawing, or at least one other danger sign.
Participants	Children aged 60 days to 12 months at the time of enrolment and excluded those with known or suspected tuberculosis, chronic respiratory or congenital heart disease, or severe malnutrition requiring hospital admission. Pneumonia was diagnosed if crepitations were heard on inspiration with a respiratory rate greater than 50 breaths per minute; severe pneumonia was diagnosed if there was also chest indrawing, or at least one other danger sign. Children with wheezing or rhonchi with crepitations were also diagnosed with pneumonia. 809 children were randomly assigned to zinc and 812 to placebo. There were no significant differences between groups at baseline, except for a slightly higher proportion of boys in the zinc group. There was no difference between the groups in serum zinc values at baseline.
Interventions	Zinc was given orally as a syrup (35 mg zinc acetate per 5 mL). The placebo was non‐nutritious and vitamin‐free. Compliance required intake of two teaspoons of syrup (10 mL). Children with pneumonia were treated with co‐trimoxazole (10 mg/kg trimethoprim, twice daily for 5 days) for pneumonia. Children on antibiotics were assessed within 72 hours of starting treatment; those who did not improve (i.e. the respiratory rate did not change by more than 5 breaths/minute from baseline) were switched to treatment with amoxicillin (40 mg/kg, three times daily for 5 days). If oral treatment failed, or if they had severe pneumonia, children were referred to hospital for parenteral treatment (ceftriaxone 75 mg/kg intramuscularly per day). Children with only expiratory wheezes or rhonchi were managed with salbutamol syrup (0.3 mg/kg, 3 times daily), or referred to hospital for danger signs.
Outcomes	Pneumonia incidence. Other outcomes included frequency of other illnesses and mortality.
Notes	Sources of funding: The research was funded by Johns Hopkins Family Health and Child Survival Cooperative Agreement with the US Agency for International Development, the Swiss Development Corporation, and a cooperative agreement between the US Agency for International Development (HRN‐A‐00‐96‐90005‐00) and core donors to the Centre for Health and Population Research.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Random assignment to zinc or placebo was done with permuted blocks of variable length between two and eight"
Allocation concealment (selection bias)	Unclear risk	Insufficient information to permit judgement
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "ACME Laboratories (Dhaka) prepared, labelled and masked the identity of both preparations. Both placebo and treatment were designed to be identical in colour, odour, and taste"; "identity of both the preparations were masked"
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Blinding of FRAs was not affected because a proportion of children in both zinc and placebo groups reacted to the taste such that the treatment could not be distinguished"
Incomplete outcome data (attrition bias) All outcomes	Low risk	Loss to follow‐up was 9.1%. Withdrawal from both groups was most commonly attributed to the child’s reaction to the taste of the syrup, which sometimes resulted in regurgitation. Most of those who withdrew were young, primarily breast fed infants. The highest proportion (37·1%) of withdrawals for both groups occurred at age 2 months, with 77·1% younger than 6 months
Selective reporting (reporting bias)	Low risk	We could not locate the protocol of this study. We could not find the trial registration number of the study. The outcomes mentioned in the methods were reported in the results
Other bias	Low risk	Study seems to be free from other biases; the funding sources had no role in the study design, data collection, data analysis, interpretation of results, or decision to publish this research Funding: The research was funded by Johns Hopkins Family Health and Child Survival Cooperative Agreement with the US Agency for International Development, the Swiss Development Corporation, and a cooperative agreement between the US Agency for International Development (HRN‐A‐00‐96‐90005‐00) and core donors to the Centre for Health and Population Research