Averill 1999.

Methods	Randomised controlled trial
Participants	Setting: not reported Duration of study: 1 year Inclusion criteria: “patients with reliable GA and a candidate for vaginal delivery.” page 47S Exclusion criteria: none stated Parity: not recorded Bishop score: not recorded
Interventions	Membrane stripping group (N = 38): weekly membrane stripping, page 47S Control group (N = 36): weekly cervical exam “Patients were randomized to WMS or a weekly cervical exam” page 47S
Outcomes	Caesarean section
Notes	Funding: none declared Trial authors’ declaration of interest: none declared Informed consent obtained: “signed the consent” page 47S Ethical approval: none declared Email sent to Dr. Averill requesting full study 10 April 2017. Resent 30 July 2017. No response to date
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“Patients were randomized“ page 47S
Allocation concealment (selection bias)	High risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants: not reported. Personnel: not reported.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not reported.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No evidence of attrition bias.“4 were lost to follow up” unknown whether pre or post randomisation. Page 47S.
Selective reporting (reporting bias)	Low risk	Maternal age, mean GA, Bishop score < 7 recorded as outcome but not reported. Page 47S.
Other bias	Low risk	Abstract only available. However, no other bias noted.