Effects of nutritional interventions during pregnancy on birth, child health and development outcomes: A systematic review of evidence from low‐ and middle‐income countries

. 2021 Jun 21;17(2):e1150. doi: 10.1002/cl2.1150

Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “A study statistician not involved in data collection generated 4 randomisation code lists in blocks of 9 (one list for each of the 4 enrolment sites)”
Random sequence generation (selection bias)	Low risk	Comment: Adequately done
Allocation concealment (selection bias)	Low risk	Quote: “The researcher sealed the slips into individual opaque randomisation envelopes, marked each envelope with the trial name and an individual participant number”
Allocation concealment (selection bias)	Low risk	Comment: Adequately done
Blinding of participants and personnel (performance bias)	Low risk	Quote: “IFA and MMN interventions were provided by using double‐masked procedures—that is, the capsules looked identical, and neither the participants nor the research team members were aware of the nutrient contents of the supplement capsules. For the LNS group, we used single‐masked procedures”
Blinding of participants and personnel (performance bias)	Low risk	Comment: Adquately done
Blinding of outcome assessment (detection bias)	Low risk	Quote: “Researchers responsible for the data cleaning remained blind to the trial code until the database was fully cleaned”
Blinding of outcome assessment (detection bias)	Low risk	Comment: Adequately done
Incomplete outcome data (attrition bias)	Low risk	Comment: IFA: 26/463 × 100 = 5.1% lost to follow‐up
Incomplete outcome data (attrition bias)	Low risk	LNS: 26/462 × 100 = 5.6% lost to follow‐up
Selective reporting (reporting bias)	High risk	Comment: Outcomes mentioned in the protocol are not completely reported in the study (NCT01239693)
Other bias	Low risk	Comment: No other potential sources of bias reported
Was the allocation sequence adequately generated?	Unclear risk
Was the allocation adequately concealed?	Unclear risk
Were baseline outcome measurements similar?	Unclear risk
Were baseline characteristics similar?	Unclear risk
Were incomplete outcome data adequately addressed?	Unclear risk
Was knowledge of the allocated intervention adequately prevented during the study?	Unclear risk
Was the study adequately protected against contamination?	Unclear risk
Was the study free from selective outcome reporting?	Unclear risk
Was the study free from other risk of bias?	Unclear risk