Inal 2006.

Methods	Parallel, active‐controlled, randomized, double‐blind, single dose over 24 h
Participants	Type of surgery: cesarean section Paracetamol group Entered/completing: 25/unclear Age (mean, SD): 30.6 ± 4.23 Sex (male, %): 0 Pethidine group Entered/completing: 25/unclear Age (mean, SD): 29.6 ± 3.51 Sex (male, %): 0
Interventions	Paracetamol 1 g/100 ml single dose over 15 min, 30 min before end of surgery pethidine 100 mg IV as above
Outcomes	Primary: VAS pain intensity at 0, 1, 5, 30 min and 1, 2, 4, 6, 8 and 24 h after surgery Secondary: Side effects Total rescue analgesic use (unspecified) over 24 h for pain > 7/10
Source of funding	Not reported
Were treatment groups comparable at baseline?	Yes: age, height, weight, duration of surgery, duration of anesthesia
Details of preoperative pain	Participants with chronic abdominal pain were excluded
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details reported
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding (performance bias and detection bias) All outcomes	Unclear risk	No details reported
Incomplete outcome data (attrition bias) All outcomes	High risk	Unclear how many participants completed the study; mean pain data did not have SDs; 24 h rescue analgesic use did not specify analgesic administered
Selective reporting (reporting bias)	Low risk	All outcomes in Methods section were reported in Results
Size	High risk	Fewer than 50 participants per arm of the study (25 paracetamol, 25 pethidine)