Tam 2005.

Methods	Single‐centre, double‐blind, randomised, controlled trial, conducted from August 1998 to July 1999 in China. Per protocol analysis. Follow‐up was 6 weeks.
Participants	170 puerperal anaemic women were screened, 150 were included and randomised into 2 groups: 75 to the intervention group, 63 completed the trial per protocol, 75 to the comparator group, 59 completed the trial per protocol. Socioeconomic conditions were not described, ethnic origin was 76% to 81% Chinese, 19% to 24% Filippino. Inclusion criteria: Hb 80 to 99 g/L 2 days postpartum. Exclusion criteria: MCV < 80 fL, significant anaemia symptoms (tachycardia, severe dizziness, and shortness of breath), estimated blood loss > 500 mL.
Interventions	Intervention referred to oral ferrous sulphate. Intervention: oral ferrous sulphate 200 mg (65 mg elemental iron) 3 times daily for 42 days. Total dose elemental iron was 8200 mg. Total dose non‐elemental iron was 25,200 mg. Comparator: placebo tablets containing lactose and drug binder 3 times daily for 42 days.
Outcomes	No preplanned outcome measures stated. Aim was to determine effects of mild postpartum anaemia and iron supplementation in women. Laboratory values, subjective evaluation of general well being score on 4‐point scale, anaemia symptoms, ability to lactate and adverse events during treatment were reported.
Notes	Source of funding was not stated. Placebo tablets contained lactose. Majority of Asian people are lactose intolerant. This may have influenced GI adverse events. In this trial anaemia symptoms in the anaemic group were compared to that of the non‐anaemic group, which did not describe the effect of treatment of the anaemic women. Authors did not respond to the request on additional information.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation table.
Allocation concealment (selection bias)	Low risk	Pharmacy responsible for randomisation, identical tablets.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Both patient and clinicians were blinded to the given treatment. However, intervention group's stool turned black.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Assuming all parties involved in the trial were unaware of treatment, risk of bias is low for all outcomes. However, women in the intervention group may have been able to guess their allocation, as it was reported that their stool turned black due to iron supplementation.
Incomplete outcome data (attrition bias) All outcomes	High risk	High dropout rate. Reason for dropout after randomisation was not described.
Selective reporting (reporting bias)	High risk	No preplanned outcome measures stated. Aim was to determine effects of mild postpartum anaemia and iron supplementation in women. Maternal mortality was not reported.
Other bias	Low risk	None known.