Hynes 2006.

Methods	Randomized, double‐blinded, double‐dummy, placebo‐ and active‐controlled Medication administered on postoperative day 1, when baseline pain reached moderate‐to‐severe intensity
Participants	Type of surgery: total hip arthroplasty Propacetamol group Entered/completing: 40/40 Age (mean, SD): 65.7 ± 9.8 Sex (male, %): 40 Diclofenac group Entered/completing: 40/40 Age (mean, SD): 65.6 ± 7.6 Sex (male, %): 55 Placebo group Entered/completing: 40/40 Age (mean, SD): 66.1 ± 7.1 Sex (male, %): 45
Interventions	Intervention: 2 g propacetamol IV Control: 75 mg diclofenac IM Placebo: double‐dummy not described
Outcomes	Pain intensity (VRS, VAS) Pain relief (categorical) Time to request for rescue medication Global assessment (categorical)
Source of funding	Supported by Bristοl‐Myers Squibb
Were treatment groups comparable at baseline?	Yes: demographics; duration of anesthesia; baseline postoperative pain
Details of preoperative pain	Not reported
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomization
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding (performance bias and detection bias) All outcomes	Low risk	Double‐dummy technique employed
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	11/40 missing pain assessment data at 5 h in intervention group due to lack of efficacy and administration of rescue dose (29/40 in placebo group), but all 40 included in efficacy analysis. Data were imputed using LOCF.
Selective reporting (reporting bias)	Unclear risk	All outcomes from Methods section reported in Results section, but time to rescue was instead reported as number of participants requesting rescue
Size	High risk	Fewer than 50 participants per arm of the study (40 propacetamol, 40 diclofenac, 40 placebo)