Lewis 1983.

Study characteristics
Methods	RCT. No details were given on the method for concealment of the allocation.
Participants	Singleton vertex term pregnancy, unfavourable cervix.
Interventions	Vaginal pessary 3 mg PGE2 (22 women); Foley catheter in the extra‐amniotic space 30 mL (22 women); Control group with no treatment (22 women; exclude)
Outcomes	Change in BS, CS, uterine hyperstimulation, AS.
Notes	Data on induction‐delivery intervals not interpretable to derive proportion of women with vaginal delivery not achieved in 24 hours. Setting: Manchester, UK 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)	Unclear risk	Random allocation, no more details reported
Allocation concealment (selection bias)	Unclear risk	Not reported
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	Unclear risk	Unclear if ITT was performed. no missing cases or data reported
Selective reporting (reporting bias)	Unclear risk	No specific pre specified outcomes reported in method section.
Other bias	Low risk	No other bias detected