Putnam 2011.

Methods	Randomised controlled trial
Participants	Setting: Obstetrics/gynecology clinic, Naval Medical Center, USA. Duration of study: January 2005 to June 2008. Participants randomised: N = 389 Inclusion criteria: “Women at 39 weeks ± 2 days gestation with an unfavorable cervix, a singleton pregnancy, ≥18 years of age, reliable pregnancy dating that included a first trimester ultrasound, ultrasound confirming that the placenta was clear of the cervix, and who had no contraindication to a vaginal delivery” (Page 288). Exclusion criteria: Bishop’s score was ≥ 4, contraindication to a vaginal delivery (Page 288). Parity: mixed. Both nulliparous and multiparous women were included (Table 1 page 290). Bishop score: Bishop score at recruitment (Table I, Page 290) and admission to labour ward (Table II, Page 291) recorded.
Interventions	Control group (n = 117): group I “cervix examined weekly but did not have their membranes swept” (Page 288). Membrane stripping 1 x/week (n = 119): Group II: “weekly membrane sweeping” (Page 288). Membrane stripping 2 x/week (n = 119): Group III: “twice‐weekly membrane sweeping.” (Page 288). “The technique of membrane sweeping was defined as separating the fetal membranes from the lower uterine segment with two circumferential sweeps by the examining finger. If the cervix did not permit entrance of the finger on examination, the finger was placed into the cervix and two circumferential sweeps were done. This was done serially depending on the frequency of the group assignment until entrance of the examining finger could be accomplished. Women in the control group had their cervix examined and the Bishops’ score recorded every 7 days. Group I women had their membranes swept every 7 days and Group II women had their membranes swept every 3–4 days. Membrane sweeping was continued according to the assigned frequency until 41 weeks of gestation. At 41 weeks, all remaining women were admitted to the hospital for labor induction.” (Page 288).
Outcomes	Induction of labour Vaginal delivery Caesarean delivery Chorioamnionitis Instrumental vaginal delivery Apgar score < 7 at 5 minutes
Notes	Funding: not stated Trial authors’ declaration of interest: not stated Informed consent obtained: not stated. Ethical approval: yes,“study was approved by the Chief of Navy Bureau of Medicine and Surgery, Washington, DC, through the local Clinical Investigation Program (International Review Board)” (Page 288).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	“The method of randomization and group assignment was determined by drawing a card from a sealed opaque envelope”, page 288.
Allocation concealment (selection bias)	Unclear risk	“The method of randomization and group assignment was determined by drawing a card from a sealed opaque envelope that would assign the participants to Group I (control), Group II (once‐weekly sweeping), or Group III (twice‐weekly sweeping). The cards were prepared in blocks of 30 envelopes”, page 288. Not reported if envelopes were sequential or numbered.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants: not reported. Personnel: partially blinded. “this study could not be blinded to the membrane sweeping investigator but was blinded to all other providers and to the investigator collecting data on each participant”, page 288.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	“this study could not be blinded to the membrane sweeping investigator but was blinded to all other providers and to the investigator collecting data on each participant”, page 288
Incomplete outcome data (attrition bias) All outcomes	Low risk	No evidence of attrition bias.
Selective reporting (reporting bias)	Low risk	No evidence of selective reporting.
Other bias	Low risk	No evidence of other bias.