Turnquest 1997.

Methods	RCT
Participants	Term women with unfavourable cervix (BS < 5), intact membranes.
Interventions	Laminaria (as many as possible) and (PGE2) vaginal gel (4 mg) (21 women); (PGE2) vaginal gel (4 mg) alone (27 women).
Outcomes	Need for oxytocin, CS, uterine hyperstimulation, admission to NICU, chorioamnionitis.
Notes	Setting: memorial hospital Indianapolis, USA Study period: October 1994 to May 1995 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 allocation sequence.
Allocation concealment (selection bias)	Low risk	Concealment of allocation by 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	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	4 women excludes because of protocol violation, no missing cases or data
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias	Low risk	No other bias detected