Elwood 1966.

Methods	Design: randomised controlled trial Randomisation: individual Trial: daily oral iron versus placebo Date of study: not stated
Participants	Setting: women living in a community near a clinic in Wales Malaria endemicity: not stated Included: women attended for a general checkup: recruited if haemoglobin 100 g/L to 135 g/L, along with a 1:2 ratio of women with haemoglobin > 135 g/L. Age range 15 years to 65 years (mean age not reported) Excluded: not stated Dropouts: 22 of 111 failed to complete study (group not stated) Sample size: total: 89; intervention: 40, control: 49
Interventions	Intervention: ferrous carbonate 200 mg daily Control: placebo Duration: 8 weeks
Outcomes	Haemoglobin, physical health, symptoms of anaemia (e.g. fatigue, concentration etc.)
Notes	Compliance: not stated Conflicts of interest: not stated Funded by: trial drugs provided by Allen and Hanburys Other notes: not stated whether SD or SE used for error. Assumed to be SD
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Placebo administered
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported.Recording of symptoms could be influenced by knowledge of allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	111 enrolled, final data from 89
Selective reporting (reporting bias)	Low risk	Not evident
Other bias	Low risk	Not evident