Awasthi 2005 (C).

Methods	Cluster‐randomised community effectiveness trial. 2 arm design with randomisation at subcentre level.
Participants	803 children, both sexes (730 females (45.4%)), aged 3‐6 years, living in sub centres of Shahpur Baxolia and Sipa Hidayatpur from Nindura Block, Barabanki district, North India. Exclusion criteria: those without written informed consent, or those likely to move within the next three months. Children identified as severely anaemic were given iron and folic acid in therapeutic doses under close supervision (but does not say they were excluded). Baseline prevalence of anaemia in children was 53.79 %. Socioeconomic status not reported.
Interventions	Sub centres were allocated to one of the following groups: Group 1 (n = 403): children in Shahpur Baxolia sub centre received tablets containing 20 mg elemental iron (presumably in form of ferrous sulphate) iron and 100 μg (0.1 mg) folic acid twice a week, on fixed days (Wednesday and Saturday); Group 2 (n = 400): children in Sipa Hidayatpur sub centre received one tablet daily. Length of the intervention: one year.
Outcomes	Haemoglobin, haemoglobin mean change, anaemia, and adherence.
Notes	Iron and folic acid was given to the children either by the Anganwadi worker, if they were registered and used the informal education services of the Integrated Child Health Development Services, or by the mother for non‐registered children. Mothers could pick up monthly supplies for their children one day a month from an Anganwadi centre. A monitoring in‐charge was responsible for each intervention type. He visited each Anganwadi centre every 15 days to take an account of the IFA distributed to registered children. The monitor in‐charge also visited 20 randomly selected houses of non‐registered children and collected information about the IFA tablet intake, including the number of pills consumed. Sample size was calculated taking into consideration a design effect of 2. We adjusted the results of this study to account for the effect of clustering in data; 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	For this study all sub centres were listed alphabetically, serially numbered, and two were selected by random for assessment of the interventional strategies, one per sub‐centre. It is unclear whether the allocation to the treatment was at random.
Allocation concealment (selection bias)	Low risk	Since the intervention was allocated at sub‐centre 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	Low risk	Loss to follow up 8.34% at one year with no difference between groups (biweekly 8.1% versus daily 8.5%).
Selective reporting (reporting bias)	Unclear risk	There is insufficient information to permit judgement.
Other bias	High risk	Some children had directly observed intake and others were given the pills by the mother. About 1/3 of the children are registered to obtain services of the Anganwadi centre (under the ICDS services) and this had a differential effect on supplementation (favouring registered children). Results did not account for the cluster effect.