Wong 2002.

Methods	Prospective randomised controlled trial
Participants	Setting: The Princess Margaret hospital, A regional obstetric unit in Hong Kong. Page 632 Duration of study: 18 months (1 July 1998 to 31 December 1999). Page 632 Participants randomised: N = 120 (133 eligible, 13 refused to participate) Inclusion criteria: “All pregnant women beyond 40 weeks of gestation, with dates determined by last menstrual periods and ultrasound performed before 26 weeks.” Page 632 Exclusion criteria: “Women with previous uterine scar, uncertain gestational age, women who refused to participate, or those who have other indications requiring early induction of labour were excluded” Page 632 Parity: mixed. Both nulliparous and multiparous women included.“Patients were stratified into two groups, namely, nulliparous and multiparous, before randomisation.”(Table 1 of manuscript page 634). However results not reported according to parity. Bishop score: not recorded
Interventions	Membrane stripping: n = 60 “Sweeping was performed by four obstetricians using a standardised method” `”As much of the membranes as possible were separated from the lower segment. If the cervix would not admit a finger it was massaged for two minutes to encourage prostaglandin release” Page 633 Control group: n = 60 “ "Women allocated into the control group did not have any form of vaginal examination”(Page 633). One woman in the control group had sweeping of membranes instead of no intervention.
Outcomes	Spontaneous onset of labour: Induction of labour Epidural Caesarean section Forceps delivery Vacuum delivery Spontaneous vaginal delivery Serious neonatal infection Neonatal perinatal death.
Notes	Funding: funded by the Hong Kong Society of Obstetricians and Gynaecologists (Page 635). Trial authors’ declaration of interest: none stated Informed consent obtained: not stated Ethical approval: yes, “study was approved by the Hospital Ethical Committee” (Page 632). Email sent 30/08/18 and 28 September 2017 requesting further information. No reply to date.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“Six different blocks of 20 randomisation codes generated by computer” Page 633.
Allocation concealment (selection bias)	Unclear risk	Page 633 “..were placed in opaque sealed envelopes. Three separate blocks of randomisation codes were kept for the nulliparous and the other three blocks for multiparous pregnant women. Envelope was opened after a date for formal induction was given”. Not reported if envelopes were sequential or numbered.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants: not reported Personnel: clinicians not blinded.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No evidence of attrition bias.
Selective reporting (reporting bias)	Unclear risk	“Sweeping was unintentionally performed in one woman randomised to the control group”, page 633. Although women were stratified by parity and subgroup analysis completed no results were reported according to parity. Author contacted for further data, no reply to date.
Other bias	Low risk	No evidence of other bias.