Jain 1988.

Methods	Randomised, double blind, 4 parallel groups. Single oral dose Medication administered when baseline pain reached a moderate to severe intensity Pain assessed at 0, 30, 60 mins, then hourly to 8 hours
Participants	Various surgical procedures, mostly Cesarian section and common gynaecological operations N = 161 M = 29, F = 132 Mean age 29 years
Interventions	Codeine 60 mg, n = 40 Diflunisal 500 mg, n = 41 Diflunisal/codeine 500/60 mg, n = 40 Placebo, n = 40
Outcomes	PI: standard 4 point scale PR: standard 5 point scale PGE: standard 5 point scale Use of rescue medication Adverse events: any, serious Withdrawals
Notes	Oxford Qualtiy Score: R1, DB1, W1. Total = 3 No details about timing of rescue medication
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