Sunawang 2009

Methods	A cluster‐randomised trial conducted in 2 subdistricts of Indramayu district of west Java province of Indonesia from May 2000 till August 2003.
Participants	Pregnant women irrespective of gestational age. Women suffering from diabetes mellitus, coronary heart disease and tuberculosis were excluded.
Interventions	Intervention group (n = 432) received RDA of 15 micronutrients according to the UNICEF/UNU/WHO recommended formula, including 30 mg of ferrous fumarate. Control group (n = 411) received ferrous sulphate 60 mg and folic acid 0.25 mg.
Outcomes	Birthweight, birth length, head and chest circumference, Hb, serum ferritin, serum zinc, serum retinol and urinary Iodine, miscarriage, stillbirths, neonatal mortality. It should be noted that the data for SGA was obtained from a separate report (Food and Nutrition Bulletin 2009) and not from the individual trial report.
Notes	Study groups were similar with respect to baseline characteristics. Supplements were given from the time of enrolment at 12‐20 weeks' gestation and continued up to 30 days postpartum.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "We restructured the 157 hamlets into 160 dwelling clusters.", "these 160 clusters (and the pregnant women living within them) were randomly assigned into 4 blocks of 40 clusters each". Comment: method used for generating the randomisation sequence is not described in sufficient detail to permit judgement.
Allocation concealment (selection bias)	Unclear risk	Comment:method used for allocation concealment is not described in sufficient detail to permit judgement.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Exclusion (< 1%) and attrition (10.4%) were reported along with their reasons.
Selective reporting (reporting bias)	Low risk	Comment: all outcomes mentioned in the methods section were presented in the paper.
Other bias	Low risk	Comment: no other bias was identified.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "This study had a single‐blind design, since the supplement for the treatment and control group looked different physically. However, participants residing in each cluster received the same supplement, so they were not aware that other participants from other clusters received a different supplement". Comment: study participants were blinded to the treatment assignment.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: " This study had a single‐blind design" comment: Blinding of outcome assessors probably not done.