Roschnik 2003 (C).

Methods	Cluster‐randomised trial. 2‐arm design with randomisation at school level and stratified by sponsorship status.
Participants	1,160 children (752 followed up), both sexes (371 females (49.5%)), aged 7–8 years and 12‐14 y. The study included 40 primary schools in the Mangochi District, Malawi. Baseline prevalence of anaemia: around 54%. Socioeconomic status not reported.
Interventions	Schools were randomly allocated to one of the following treatments: Group 1 (20 schools, n = 640): children received 65 mg of elemental iron (as 200 mg ferrous sulphate) and 250 μg (0.25 mg) of folic acid once a week. Group 2 (20 schools, n = 640): children received no intervention. Length of the intervention: 15 weeks
Outcomes	Haemoglobin concentration, bilharzia infection, school attendance, test scores and drop‐out rate and repetition rate (at the school level).
Notes	Results were stratified by age (<10 y, 10‐14 y and 15+). For the purposes of this review we only included those data from children <10 years of age (192 in the intervention group and 190 in the control group), until we can obtain the data for all children <12 years. A famine occurred in the region at the time of the study. Each study group included 10 sponsorship schools and 10 non‐sponsorship schools, 10 coastal and 10 upland schools. All children in Coastal intervention and comparison schools, where the prevalence of bilharzia was over 50%, were dewormed with Praziquantel (600mg) just after the baseline survey. A vitamin A capsule (200,000 IU) was given to all children in standard 2 and below 63% of children took 10 iron tablets or more. Analysis originally not adjusted by the effect of clustering. The effective sample was calculated by imputing the ICC from Roschnik 2004 (C), which has a similar study design; the estimated effective sample size was used in the analyses.  Malaria endemicity not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	40 primary schools in the Mangochi District were randomly divided into the intervention (1st iron group) and comparison group (2nd iron group). Each group includes 10 sponsorship schools and 10 non‐sponsorship schools. Method of sequence generation not specified.
Allocation concealment (selection bias)	Low risk	Not reported. Since the intervention was allocated at school level, it is unlikely there was a selection bias at the individual level.
Blinding (performance bias and detection bias) All outcomes	High risk	Participants: not reported. Personnel: not reported Outcome assessors: not reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	1280 were randomised, 1160 had haemoglobin levels at baseline and 752 were followed up: 41.2% children lost to follow up
Selective reporting (reporting bias)	Unclear risk	There is insufficient information to permit judgement.
Other bias	Unclear risk	Children attending sponsored schools responded better to the treatment.