Policiano 2017.

Study characteristics
Methods	RCT – blocked randomisation in 10s.
Participants	Inclusion criteria Women with a single fetus in cephalic presentation, Bishop score < 6. Gestational age ≥ 41 weeks or medical indication for IOL (high‐risk pregnancy group). Number of women randomised and analysed: N = 130. Exclusion criteria Women with a fetus in non‐cephalic presentation, an indication for elective caesarean delivery, spontaneous labour, hydramnios (amniotic fluid index ≥ 25), non reassuring cardiotocogram, multiple pregnancy, rupture of membranes, active vaginal bleeding, indication for prophylaxis of Streptococcus group B infection, HIV infection, cervical injury or previous caesarean section with recurrent indication.
Interventions	Intervention: home IOL with Foley catheter Women were only discharged after a reassuring cardiotocogram following the introduction of Foley catheter. When discharged, women were instructed to apply manual traction to the catheter every 6 hours and were given a written document with all the information that should bring them back to the hospital, such as: spontaneous catheter expulsion; loss of amniotic fluid or blood; pain or severe discomfort; decreased fetal movements; painful contractility (> 1 contraction/10 minutes) and fever (T > 380C). If the catheter was not extruded until after 24 hours, women should return to the hospital for re‐evaluation and hospitalisation. Total number randomised to this group: N = 65 Comparator: inpatient IOL with Foley catheter Women were monitored and oriented in accordance to the Department’s protocol. Total number randomised to this group: N = 65 Comparison and subgroups Comparison 3: IOL with balloon or Foley catheter Subgroup by parity: S3 ‐ not reported Subgroup by membrane status: S1 intact Subgroup by cervical status: S1 unfavourable Subgroup by indication for induction: S3 ‐ mixed
Outcomes	Primary: change of Bishop score (difference between BS before and after application of FC). To detect a difference of at least 1 point change in BS between groups maintaining a power of 80% with an a level of 0.05 we calculated a sample of 60 patients in each group. Secondary: induction‐to‐delivery time, inpatient time, mode of delivery, cervix length change (difference between cervix length measured by transvaginal ultrasound before and after application of FC), failed induction rate, tachysystole with fetal decelerations, intrapartum and postpartum fever 380C, maternal pain, maternal and neonatal morbidity and mortality
Notes	Setting: tertiary hospital (from trial registration form). Authors from Lisbon, Portugal Trial dates: January 2014 to December 2015 Sources of trial funding: the authors report no financial support (sponsors were Hospital de Santa Maria, Lisbon, Portugal) Trial authors' declarations of interest: the authors report no conflict of interest. Additional information Quote: "Our protocol for mechanical cervix priming uses a single balloon (CovidianTM DoverTM Silicon Coated Latex Foley catheter 16Fr/Ch 5.3 mm) in an inpatient setting. A deflated catheter is introduced through the outer cervix orifice under direct visualisation using a sterile speculum and after iodine disinfection of the cervix. The intracervical catheter is distended with 40 mL of a saline solution. The end of the catheter is taped to the medial portion of the thigh and manual traction is applied to the catheter every 6 hours. If no spontaneous extrusion it is removed after 24 h. The induction of labor is carried out in accordance with BS." Quote: "In our Department, we use prostaglandins if BS < 6 or oxytocin if BS ≥ 6. Our standard regimen of misoprostol is vaginal administration of 25mcg every 4 h for a total of 5 administrations. In case of BS < 6 after 24 h of misoprostol, the woman rests for 24 h and then restarts a new cycle of misoprostol administrations. Prostaglandins are not used in case of previous uterine scar. Before or during priming with Foley catheter no antibiotic prophylaxis is performed." Authors report caesarean births for failed induction (2/65 vs 11/65) but not total caesarean births, and although they also report vaginal births (47/65 vs 40/65), we are writing to authors for data on spontaneous vaginal births, instrumental vaginal births and overall caesarean births.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote:“…computer‐generated random numbers.”
Allocation concealment (selection bias)	Low risk	Quote: “Allocation was initially concealed. An envelope was opened for all consecutive participants to reveal their group assignment at the time when they were recruited into the study.”
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding of location was not possible for this comparison, and this may have influenced subjective outcomes although not objective outcomes.
Blinding of outcome assessment (detection bias) All outcomes	High risk	No information provided so it is very likely the clinician giving care knew the allocation, particularly for the assessment of change in Bishop score and many clinical outcomes.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All data collections appear complete.
Selective reporting (reporting bias)	High risk	Appears not to report fully on mode of birth – gave vaginal births but no differentiation between spontaneous and instrumental. Only gave caesarean section for failed induction, not overall. Do not appear to report ‘failed induction’ though maybe can use PG induction data for this. We did not assess the trial protocol.
Other bias	Unclear risk	Baseline characteristics were similar. Block randomisation of 10 may possibly have introduced some bias. No other biases were identified.