Biron‐Shental 2004.

Study characteristics
Methods	Randomised trial.
Participants	Term, singleton pregnancy BS 4 or less, medical indication for labour induction.
Interventions	PGE 2 gel 2 mg (27). Double balloon catheter (26) combined (24)
Outcomes	Change in BS, need for oxytocin augmentation.
Notes	Outcomes of interest not reported. Setting: Israel Study period: not reported Funding: not reported Declarations of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated sequence.
Allocation concealment (selection bias)	Unclear risk	Not mentioned.
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 described
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Brief communication, for the reported data no missing. Incomplete outcome data not further mentioned in this report.
Selective reporting (reporting bias)	Unclear risk	Our outcomes of interest are not reported here, main outcome is change in BS.
Other bias	Unclear risk	Hard to say, very short report, our outcomes of interest not mentioned, not clear how sample size was calculated.