Chookijkul 2016.

Methods	Randomised trial.
Participants	Inclusion: women in the latent phase of labour and with a need for labour induction or augmentation, gestational ages of 37 to 42 weeks, cephalic presentation, estimated fetal weight < 4000 g, Bishop score > 4. Exclusion: malpresentation, previous uterine surgery, placenta previa, placental abruption, persistent non‐reassuring fetal heart rate‐pattern, PROM, active phase of labour, fetal abnormalities, severe maternal diseases (i.e. pre‐eclampsia, diabetes, HIV, heart disease). Setting: Bhumibol Adulyadej Hospital, Thailand, February 2014 to January 2015 (period of inclusion). Number of included participants: 170 in the continued group and 170 in the discontinued group.
Interventions	Oxytocin infusion Saline infusion When there was a cervical dilation of 4 cm, the infusion was replaced with infusion containing either oxytocin or placebo. Amniotomy was not performed prior to stimulation. No available information on infusion rate/dosage.
Outcomes	Primary: Caesarean delivery Secondary: Duration of labour Total dose of oxytocin Chorioamnionitis Postpartum haemorrhage Non‐reasurring fetal heart rate pattern Apgar score Birthweight NICU admission
Notes	The difference in caesarean rate observed in this trial was entirely in caesareans performed in the latent phase (26 versus 19). i.e. on women who had not experienced the trial intervention because labour had not proceeded that far. Among women who reached the active phase, who presumably had the oxytocin infusion stopped or not, the caesareans did not differ (28 versus 28). Discontinued group 9.4% non‐compliance (had oxytocin restarted due to lack of progression). Sources of trial funding: Bhumibol Adulyadej Hospital Research Fund. Trial authors declare no conflict of interest. Trial was registered May 03, 2015, after the trial had completed in January 2015.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation.
Allocation concealment (selection bias)	Unclear risk	Sealed and opaque envelopes, not numbered. Perfect balance (170 per group) between groups suggests no post randomisation exclusions (due to lost envelopes) and no post randomisation compliance problems, i.e. no women delivered before the envelope could be opened and the investigational infusion connected and started.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Oxytocin and placebo was prepared by 1 pharmacist who did not attend or take responsibility for attending cases. It was labelled by running numbers.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Oxytocin and placebo was prepared by 1 pharmacist who did not attend or take responsibility for attending cases. It was labelled by running numbers.
Incomplete outcome data (attrition bias) All outcomes	High risk	Intention‐to‐treat principles were followed. Missing values are not reported. Trial registration after completion. Secondary outcomes not fully specified on trial register. Operative vaginal delivery (forceps or ventouse), cord pH, perinatal and neonatal deaths, not reported. PPH reported but not defined. Apgar scores at 1 and 5 minutes reported only as quote: "equally excellent in both groups".
Selective reporting (reporting bias)	High risk	No protocol was published prior to article. Trial was registered May 03, 2015, after the trial had completed in January 2015.
Other bias	Unclear risk	No other source of bias noted.