Breen 1999.

Methods	Randomisation: computer‐generated randomisation in blocks of 4 with allocation concealed in sealed envelopes. Blinding: procedure performed by an anaesthesiologist not involved in subsequent assessments. Both assessor and participant blinded to allocation. Criteria for rescue analgesia: not specifically stated. Statistics were not performed on an intention‐to‐treat basis. One woman in the epidural group was excluded due to loss of blinding, and data from this participant were not used in analysis.
Participants	Inclusions: 41 participants were initially enrolled into the study, all ASA class 1 or 2, at least 18 years old, with a singleton fetus with cervical dilatation < 6 cm. Exclusions: inability to give informed consent, allergy to study drugs and contraindication to regional blockade. No. lost to follow‐up: 1 woman in epidural group dropped from analysis due to loss of blinding.
Interventions	Epidural (n = 20): all women received 750 to 1000 mL crystalloid prior to epidural insertion. The initial epidural bolus was a 3 mL test dose of 1.5% lidocaine with 1:200,000 epinephrine. This was followed 3 min later with a bolus 100 µg fentanyl diluted to a volume of 10 mL with saline down the epidural catheter. The study period ended with the first request for additional analgesia. CSE (n = 21): single space, needle‐through‐needle. An intrathecal injection of sufentanil 10 µg diluted to 2 mL with saline. The epidural catheter was placed in the same manner as for the epidural group, but no drugs were given down it until additional analgesia was requested, at which point the study period ended.
Outcomes	Primary outcome was time from injection of narcotic until request for additional analgesia (duration of analgesia). VAS pain scores were assessed at 0, 5, 10, 15 and 30 min, and thereafter every 30 min. Motor block on Bromage scale was assessed at 30 min. Ability to walk and void urine was only assessed in those with full motor power. The incidence of itch was assessed by VAS scores.
Notes	Canada.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation in blocks of 4.
Allocation concealment (selection bias)	Low risk	Used opaque, sealed envelopes.
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐blinded, both women and the anaesthesiologist collecting the data were blinded.
Incomplete outcome data (attrition bias) All outcomes	Low risk	One woman in epidural group dropped from analysis due to loss of blinding.
Selective reporting (reporting bias)	Low risk	Primary and secondary outcomes were reported except for one epidural group patient.
Other bias	Low risk	No other bias evident.