Hiller 2004.

Methods	Randomized, double‐blind, active‐controlled Medications administered immediately after induction of anesthesia (surgeries averaged around 30 min)
Participants	Type of surgery: elective tonsillectomy Propacetamol group Entered/completing: 26/25 Age (mean, SD): 29 ± 11 Sex (male, %): 52 Diclofenac group Entered/completing: 25/25 Age (mean, SD): 27 ± 7 Sex (male, %): 44
Interventions	Intervention: 2 g propacetamol in 100 ml normal saline Control: 75 mg diclofenac Control: 2 g propacetamol plus 75 mg diclofenac (not included in our analysis)
Outcomes	Opioid consumption (oxycodone) Pain intensity at rest and on swallowing (VRS, VAS) Patient satisfaction (VAS)
Source of funding	Not reported
Were treatment groups comparable at baseline?	Yes: demographics; duration of surgery, intraoperative opioid use; blood loss
Details of preoperative pain	Not reported
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described
Allocation concealment (selection bias)	Low risk	Sealed envelope method
Blinding (performance bias and detection bias) All outcomes	Low risk	Nurse preparing solutions did not participate in the study. To maintain double‐blind design volumes infused were equal.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Various reasons for dropouts amongst groups, data analyzed in completers only, but minimal missing data
Selective reporting (reporting bias)	Unclear risk	Outcomes not specified in Methods section; possibility of additional post‐hoc analyses cannot be ruled out
Size	High risk	Fewer than 50 participants per arm of the study (26 propacetamol, 25 diclofenac)