Jayr 1998.

Methods	RCT Ethics committee approval and written informed consent obtained from each patient Setting: France Funding: industry
Participants	141 ASA 1 to 3 patients aged 18 to 75 years and weighing 50 to 110 kg undergoing elective open major abdominal (urological, gynaecological or gastrointestinal)
Interventions	Treatment group: TEA (T12‐L1; level according to surgical site) with 0.2% ropivacaine started after surgery and kept for 24 hours (n = 38) Control group: IV PCA with morphine (n = 46) General anaesthesia for all participants
Outcomes	Vomiting
Notes	A third group with epidural ropivacaine plus IV morphine was not retained Study authors contacted for additional information; referred us to AstraZeneca, which did not reply
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomisation code envelopes"
Allocation concealment (selection bias)	Low risk	Envelopes opened just before preparation for anaesthesia
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	11 losses to follow‐up
Selective reporting (reporting bias)	Low risk	All results reported
Other bias	Unclear risk	More women in the PCA group Not in intention‐to‐treat