Hahn 2003.

Methods	Randomized, double‐blinded, placebo‐controlled Medications administered after surgery and immediately before extubation
Participants	Type of surgery: laparoscopic sterilization Propacetamol group Entered/completing: 15/15 Age (mean, SD): 36 ± 4 Sex (male, %): 0 Placebo group Entered/completing: 16/16 Age (mean, SD): 37 ± 4 Sex (male, %): 0
Interventions	Intervention: 40 mg/kg propacetamol Control: 20 mg/kg propacetamol (not included in our analysis) Control: 10 mg/kg propacetamol (not included in our analysis) 1 g propacetamol was dissolved in 5 ml of contained solvent and administered as bolus Placebo: normal saline
Outcomes	Opioid consumption (alfentanil via PCA) Postoperative pain at rest and with movement (10 cm VAS)
Source of funding	SmithKline Beecham, Denmark supported the study. The infusion pumps were supplied by Baxter, Denmark.
Were treatment groups comparable at baseline?	Yes: demographics and duration of anesthesia
Details of preoperative pain	Patients were excluded if they had a history of chronic pain
Notes	40 mg/kg dose chosen in analysis as, based on participant weights, this would be closest dose to standard 2 g of propacetamol
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Blocked randomization
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding (performance bias and detection bias) All outcomes	Low risk	Drugs were administered by an anesthetist who had no further contact with the participant or study personnel
Incomplete outcome data (attrition bias) All outcomes	Low risk	Minimal number of dropouts; it appears that all other data reported for remaining participants and at all relevant time points
Selective reporting (reporting bias)	Unclear risk	Time points not specified in Methods section for primary outcome; data pooled for different dosing regimens post 3 h
Size	High risk	Fewer than 50 participants per arm of the study (15 propacetamol, 16 placebo)