Roztocil 1998.

Study characteristics
Methods	Allocation according to the week of admission. No concealment of allocation.
Participants	Singleton vertex term pregnancies, BS < 5. Excluded if labour, fetal hypoxia, previous CS.
Interventions	Dilapan S 4 units, removed after 14 hours (82 women); PGE2 intracervical gel 0.5 mg, 1 dose (83 women). In both groups, PGE2 vaginal tablets were administered after 14 hours for labour induction.
Outcomes	CS, hyperstimulation with FHR changes, instrumental vaginal delivery, AS < 7, GI side effects, haemorrhage.
Notes	Inadequate method of random allocation and of concealment of allocation. Setting: obstetrics department Brno, Chech Republic Study period: January 1994 to December 1996 Funding: not reported Declarations of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Allocation according to the week of admission.
Allocation concealment (selection bias)	High risk	No concealment of allocation
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	Low risk	ITT not reported, but seems reasonable as numbers are equal to randomised numbers. no missing cases or data
Selective reporting (reporting bias)	Low risk	Pre‐specified outcomes reported
Other bias	Low risk	No other bias detected