Ojo 2020.

Study characteristics
Methods	Prospective, randomised, double‐blind controlled trial
Participants	Inclusion criteria: American Society of Anesthesiologists physical status II and III women >18 years of age, at gestational age >36 weeks, with singleton pregnancies, vertex presentation, in labour, desiring epidural labour analgesia at cervical dilation between 2 cm and 7 cm and reporting a verbal pain score >5
Interventions	AMB (n = 61): Initial loading dose of 20 mL 0.1% ropivacaine with 2 µg/mL fentanyl then 6 mL programmed intermittent epidural boluses every 45 minutes with the first bolus administered 30 minutes after epidural initiation BI (n = 59): Initial loading dose of 20 mL 0.1% ropivacaine with 2 µg/mL fentanyl then 8 mL/h infusion beginning immediately after the loading dose
Outcomes	Rate of breakthrough pain with need for anaesthetic intervention Rate of caesarean delivery Rate of instrumental delivery Duration of labour Time‐weighted consumption of LA Maternal satisfaction Apgar scores
Notes	Study dates: November 2016 to November 2017 Funding sources not declared Conflicts of interest declared: A. S. Habib is a senior editor for Anesthesia and Analgesia
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation by computer‐generated assignment: Quote: "After obtaining informed consent, subjects were allocated to a study arm (continuous epidural infusion or programmed intermittent epidural boluses) by computer‐generated random assignment placed in sequentially numbered sealed opaque envelopes."
Allocation concealment (selection bias)	Low risk	Allocation concealment by sequentially numbered sealed opaque envelopes: Quote: "...placed in sequentially numbered sealed opaque envelopes."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Patient, anaesthesia provider and outcome assessor were blinded: Quote: "The patient, anesthesia provider, and outcome assessor were blinded to the randomization assignment."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors were blinded: Quote: "The patient, anesthesia provider, and outcome assessor were blinded to the randomization assignment."
Incomplete outcome data (attrition bias) All outcomes	High risk	Over 30% of study population excluded from analysis.
Selective reporting (reporting bias)	Low risk	All a priori outcomes reported based on published protocol
Other bias	Low risk	Appears to be free of other sources of bias. Sample size calculation: sample size of 44 women per group had 91% power to identify a difference in LA consumption based on pilot study