Juhl 2006.

Methods	Randomized, double‐blind, double‐dummy, active‐ and placebo‐controlled Medication administered when baseline pain reached moderate‐to‐severe intensity within 6 h of surgery
Participants	Type of surgery: third molar extraction Paracetamol group Entered/completing: 132/132 Age (mean, SD): 25.0 ± 2.6 Sex (male, %): 41 Placebo group Entered/completing: 33/33 Age (mean, SD): 25.2 ± 2.8 Sex (male, %): 55
Interventions	Intervention: IV paracetamol 1 g Control: IV paracetamol 2 g (not included in our analysis) Placebo: 100 ml solution All interventions administered in 100 ml solution for each 1 g of paracetamol (or placebo) over 15 min
Outcomes	Pain relief (VAS and VRS) and derived TOTPAR Pain intensity (VAS and VRS) Time to request of rescue medication Global evaluation (categorical)
Source of funding	Supported by Bristol‐Myers Squibb Company
Were treatment groups comparable at baseline?	Yes: demographics; ASA classification; number of teeth removed; baseline postoperative pain intensity; surgical trauma No: longer duration of surgery in the IV paracetamol 1 g group in comparison with the IV paracetamol 2 g and placebo groups
Details of preoperative pain	Participants with other painful physical conditions that might confound pain assessment were excluded
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Block randomization 4:4:1, each block n = 9
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	Low risk	A double‐dummy method was used to assure double‐blinding
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	ITT analysis using LOCF. Unclear how many participants had data imputed.
Selective reporting (reporting bias)	Low risk	All outcomes from Methods section reported in Results section, but SPID was only calculated using categorical pain intensity despite being measured with both categorical and VAS scales
Size	Unclear risk	50 to 199 participants per arm of the study (132 paracetamol, 33 placebo)