Licker 1994.

Methods	RCT Approved by the ethics committee and written informed consent obtained Setting: Switzerland Funding: unspecified
Participants	19 women with ASA 1 to 2 undergoing abdominal hysterectomy
Interventions	Treatment group: lumbar epidural analgesia with bupivacaine and fentanyl adjusted to keep the participant free of pain (n = 9) Control group: IV morphine PCA (n = 9) All participants were given a propofol‐based general anaesthesia
Outcomes	VAS scores at 8 and 24 hours (taken as at rest; not clearly written)
Notes	No complications occurred in any participants during the hospital stay
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly assigned, no details
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not mentioned
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned
Incomplete outcome data (attrition bias) All outcomes	Low risk	Initially, 10 participants in the epidural group; 1 excluded because of failure of a device required for the main objective of the study
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Unclear risk	Groups well balanced Initially, 10 participants in the epidural group; 1 excluded because of failure of a device required for the main objective of the study. Therefore, not in intention‐to‐treat