Browne 2011.

Study characteristics
Methods	RCT
Participants	Inclusion criteria: single, live fetus, cephalic, presentation,reassuring fetal health assessment, GA between 26 and 42 weeks, Maternal age 18 and above, BS less than 5 Exclusion criteria: multiple gestation (twins, triplets, quadruplets), fetal demise Fetal malpresentation, EFW less than 500 g or more than 4000 g, placenta previa, non‐reassuring fetal health assessment Maternal asthma, Latex allergy, spontaneous labour, other contraindication to vaginal delivery
Interventions	Balloon: (n = 34): 40 mL, under traction, max 6 hours. PGE2 vaginal (36): prepidil gel in fornix posterior, no oxytocin in 6 hours after gel is applied balloon and PGE2 (31): 40 mL, under traction. prepidil gel inserted through catheter.
Outcomes	CS
Notes	Grey literature: not published. primary outcomes reported in trial registration Setting: USA Study period: July 2010 ‐ February 2013 Funding: not reported Declarations of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation envelopes prepared by statisticians at the University of South Carolina Arnold School of Public Health. The investigator was given the next sequentially‐numbered study envelope by the patient's nurse.
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not feasible due to nature of intervention
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	ITT not reported. case missing for relevant outcome (CS)
Selective reporting (reporting bias)	High risk	Only primary outcome en adverse events reported
Other bias	Unclear risk	Study not published, not clear why.