Bentley 1987.

Methods	R, DB, 4 parallel groups. Single oral dose Medication administered when baseline pain reached moderate to severe intensity Pain assessed at baseline then hourly up to 5 hours
Participants	Oral surgery involving impacted tooth or removal of bone N = 128 (120 analysed for efficacy) M = 46, F = 74 Mean age 25 years
Interventions	Codeine 60 mg, n = 21 Paracetamol 1000 mg, n = 41 Paracetamol + codeine 1000/60 mg, n = 41 Placebo, n = 17
Outcomes	PI: non‐standard 10 point scale PR: standard 5 point scale PGE: standard 5 point scale Use of rescue medication Adverse events Withdrawals
Notes	Oxford Qualtiy Score: R1, DB1, W1. Total = 3
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Not described
Allocation concealment?	Unclear risk	Not described
Blinding? All outcomes	Unclear risk	Not described