| Methods |
Prospective randomised trial conducted between November 2008 and August 2010. |
| Participants |
154 nulliparous women carrying live singleton fetuses in cephalic presentation admitted for induction of labour at the Seoul National University Bundang Hospital (Seongnamsi, Korea). Inclusion criteria included nulliparity, singleton pregnancy, live fetus with vertex presentation, intact amniotic membranes, at least 37 weeks' gestation, absence of labour and no previous uterine surgical procedures. |
| Interventions |
Bishop score, transvaginal ultrasonography. |
| Outcomes |
Need for prostaglandin, need for oxytocin induction, interval to active phase, induction delivery interval, vaginal delivery within 24 hours, rate of caesarean section. |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Random sequence generation was adequately generated. "Women agreeing to participate in the study were assigned...by means of computerised random number generator." |
| Allocation concealment (selection bias) |
Low risk |
Allocation concealment was adequate. "Group allocation was predetermined and placed in sequentially numbered, sealed opaque envelope...." |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
Both participants and personnel were blinded. "Envelopes were prepared by a research nurse who was not involved in the clinical care." "...cervical examination by transvaginal ultrasound and digital clinical examination was performed by separate examiners, blinded to each other's results". "Group allocation was not revealed to the women or attending physician." |
| Blinding of outcome assessment (detection bias) |
Low risk |
The outcome assessor was not aware of the interventions for each participant. "Group allocation was not revealed to the women or attending physician." |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Intention‐to‐treat analysis, low rate of attrition. |
| Selective reporting (reporting bias) |
Low risk |
All proposed outcome measures were reported. |
| Other bias |
Unclear risk |
It was not clear if there was any other source of bias. |
