Rouben 1993.

Methods	RCT. Allocation sequence from a table of random numbers. Blocks of 6 women. Concealment of allocation by sequentially‐numbered, sealed, opaque envelopes.
Participants	Singleton vertex term pregnancies, intact membranes, BS < 6. Excluded if non‐reassuring FHR, placenta praevia.
Interventions	Foley catheter inflated with 30 mL water and extra‐amniotic infusion of 1 mL/minute saline during up to 8 hours (56 women); PGE2 vaginal gel 2.85 mg (56 women).
Outcomes	BS change, CS, uterine hyperstimulation, NICU admission, chorioamnionitis, spontaneous labour, failure of induction, endometritis.
Notes	Also reported as abstract (Arias 1993). Setting: St. Louis, USA Dates of 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	Random number table
Allocation concealment (selection bias)	Low risk	Consecutively‐numbered, opaque, 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	No information
Incomplete outcome data (attrition bias) All outcomes	High risk	ITT not reported, women with failed induction excluded from further analysis
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes reported
Other bias	Low risk	No other bias detected