Morau 2019.

Study characteristics
Methods	Prospective, controlled, randomised, triple‐blind
Participants	Inclusion criteria: nulliparous term women, aged 18 to 44 years, with a healthy singleton pregnancy and a foetal vertex position, in spontaneous labour with cervical dilation of 4 cm or less and a pain score more than 4 on a 0 to 10 verbal numeric pain scale
Interventions	AMB (n = 124): 0.1% levobupivacaine with sufentanil 0.36 µg/mL 8 mL bolus every hour beginning 60 minutes after loading dose of 15 mlLof 0.1% levobupivacaine and 10 µg of sufentanil. PCEA with patient requested boluses of 8 mL, with a 10 min refractory period and a maximum hourly dose of 24 mL. BI (n = 125): 0.1% levobupivacaine with sufentanil 0.36 µg/mL at 8 mL/h infusion after loading dose of 15 mL of 0.1% levobupivacaine and 10 µg of sufentanil. PCEA with patient requested boluses of 8 mL, with a 10 min refractory period and a maximum hourly dose of 24 mL.
Outcomes	Number of anaesthesiologist intervention due to breakthrough pain Rate of caesarean delivery (then excluded from analysis) Rate of instrumental delivery Duration of labour Time‐weighted consumption of LA Maternal satisfaction Apgar scores
Notes	Study dates: January 2014 to June 2016 Funding sources: Research grant from the French Society of Anesthesiology and Intensive Care (SFAR), 75016 Paris. This study was funded by Smiths Medical France, 94656 Rungis Cedex. The study sponsors had no role in study design or in the writing of the report. Conflict of interests declared: Lead author reports receiving payment for the development of educational support on post partum haemorrhage from LFB (Laboratoire Francais des Biotechnologies) in 2017 and reimbursement of meeting fees and travel expenses from Smith Medical France, LFB and Grunenthal in 2015 and 2016.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of randomisation was not stated: Quote: "Patients were randomised by blocks of 4 and 6, and randomisation was stratified by centre."
Allocation concealment (selection bias)	High risk	No allocation concealment was performed: Quote: "The anaesthesia nurse allocated the patient to a group according to the randomisation list..."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Participants and clinical team were blinded: Quote: "The anaesthesiologist, the obstetrician and the patient were all blind to the group assignment."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The anaesthesiologist, the obstetrician and the patient were blinded to the group assignment: quote: "The anaesthesiologist, the obstetrician and the patient were all blind to the group assignment."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low attrition: 25 of 149 (16.7%) participants in AMB group excluded from analysis and 24 of 149 (16.1%) participants in BI group 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 of 300 would allow the detection of an absolute difference of 15% in the rate of the primary outcome, with a power of 80% and an alpha risk of 5%.