Capogna 2011.

Study characteristics
Methods	Prospective randomised double‐blind controlled study
Participants	Setting: recruited from Citta di Roma Hospital, Roma, Italy Sample size: N = 150 (N completers = 145) Participants: age 27 ± 5 years (BI) and 29 ± 5 years (AMB) Inclusion criteria: healthy, nulliparous, term women with singleton, vertex pregnancies in spontaneous labour if cervical dilation was < 4 cm and if her baseline pain score, assessed at the peak of the contraction, was > 50 mm on a 100 mm visual analogue pain scale (VAPS) 5 women in the continuous epidural infusion group excluded: 4 reported VAPS > 10 mm 30 min after the epidural injection and one unintentional epidural catheter dislodgement during labour
Interventions	AMB (n = 75): 0.0625% levobupivacaine with sufentanil 0.5 µg/mL, 10 mL every hour, beginning 60 min after the administration of the initial epidural loading dose. PCEA pump was programmed to deliver 5 mL patient‐activated boluses of levobupivacaine 0.125% with a lockout interval of 10 min and a per hour maximum volume of 15 mL BI (n = 70): 0.0625% levobupivacaine with sufentanil 0.5 µg/mL, 10 mL/h, beginning immediately after the administration of the initial epidural loading dose. PCEA pump was programmed to deliver 5 mL patient‐activated boluses of levobupivacaine 0.125% with a lockout interval of 10 min, and a per hour maximum volume of 15 mL
Outcomes	Rate of breakthrough pain with need for anaesthetic intervention Rate of caesarean delivery Rate of instrumental delivery Duration of labour Total dose of LA (levobupivacaine)
Notes	Study dates: April 2009 to July 2010 Funding sources not declared No conflict of interests declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "During epidural catheter placement, a sequentially numbered, opaque envelope containing the group assignment (computer‐generated random‐number sequence) was opened by an unblinded researcher who set up the 2 epidural pumps according to group allocation."
Allocation concealment (selection bias)	Low risk	Quote:"During epidural catheter placement, a sequentially numbered, opaque envelope containing the group assignment (computer‐generated random‐number sequence) was opened by an unblinded researcher who set up the 2 epidural pumps according to group allocation."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote:"The subjects and other study personnel were blinded to group assignment and all the observations and assessments were performed by a researcher blinded to the mode of drug administration."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote:"The subjects and other study personnel were blinded to group assignment and all the observations and assessments were performed by a researcher blinded to the mode of drug administration."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition and exclusions reported; 5 out of 150 participants dropped out; however, this dropout rate is not significant (3%).
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 70 participants in each group had a power of at least 80% for a 2‐sided Chi2 test of association between maintenance technique and incidence of motor block, with a significance level set to 0.05.