USA 1994.

Methods	'Prospectively enrolled and randomly assigned'; no further information was given. 3‐arm comparison trial.
Participants	124 women having GDM screening at 24 to 28 weeks' gestation or women at high risk at initial antenatal visit; partial initial outcome data reported following screening of 122 women O'Sullivan 1964 criteria were used to diagnose GDM. Settings: Medical Education Clinics, Saint Luke's Hospital, Kansas City, Missouri, USA.
Interventions	Experimental group 1: 40 women, 50 g glucose polymer. Experimental group 2: 39 women, candy bars as a screening test. Control: 43 women, 50 g standard d‐glucose. In all groups the intervention was non‐fasting, regardless of when the last meal was eaten. Serum glucose at 1 hour, then 100 g oral GTT within 1 week, 16 were unable to complete the GTT; 5 because of vomiting and 11 for logistical or laboratory reasons.
Outcomes	Women: serum glucose at 1 hour ≥ 7.5 mmol/L, rating for taste and adverse symptoms (including pain, bloating, dizziness and nausea). Babies: none reported.
Notes	5 women required nursing assistance to complete the GTT. Control group data were divided (to prevent double counting) and were compared with data from the 2 experimental groups. Study dates: not reported. Funding sources: research grant from St Luke’s Foundation; declarations of interest: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	'Randomly assigned'; no further information was given.
Allocation concealment (selection bias)	Unclear risk	Concealment of allocation was not reported.
Incomplete outcome data (attrition bias) All outcomes	High risk	16/124 (13%) did not have a GTT (5 because of vomiting, 11 for 'logistical' reasons or because of incomplete laboratory data). 14/108 (13%) women did not complete the post‐test questionnaire.
Selective reporting (reporting bias)	Low risk	Specified outcomes of serum glucose at 1 hour and questionnaire for taste and symptoms were reported.
Other bias	High risk	Differences in group characteristics were significant for age and parity (younger and lower parity women received candy bars).
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding was not reported, but treatments were visibly different (candy bar vs solution). Reporting of side effects could have been affected by knowledge of treatment groups, but serum glucose value would not have been affected.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding was not reported. Symptoms were self‐reported on a questionnaire and were not subject to assessor bias. Plasma glucose values would not have been affected by lack of blinding on the part of assessors.

ADA: American Diabetes Association
 d‐glucose: glucose monomer
 GDM: gestational diabetes mellitus
 GTT: glucose tolerance test
 OGTT: oral glucose tolerance test
 SD: standard deviation
 vs: versus
 WHO: World Health Organization