Comparison 1. Pre‐emptive NSAIDS/COX‐2 inhibitors versus post‐incision NSAIDS/COX‐2 inhibitors.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1.1 Early acute postoperative pain (within 6 hours postoperatively)	36	2032	Mean Difference (IV, Random, 95% CI)	‐0.69 [‐0.97, ‐0.41]
1.2 Nausea and vomiting (short‐term)	2	100	Risk Ratio (M‐H, Random, 95% CI)	1.00 [0.34, 2.94]
1.3 Nausea and vomiting (long‐term)	5	228	Risk Ratio (M‐H, Random, 95% CI)	0.85 [0.52, 1.38]
1.4 Late acute postoperative pain (24‐48 hours postoperatively)	28	1645	Mean Difference (IV, Random, 95% CI)	‐0.22 [‐0.44, 0.00]
1.5 24‐hour morphine consumption (mg)	16	854	Mean Difference (IV, Random, 95% CI)	‐5.62 [‐9.00, ‐2.24]
1.6 Time to first analgesic request (minutes)	18	975	Mean Difference (IV, Random, 95% CI)	17.04 [3.77, 30.31]
1.7 Pruritus (long‐term)	4	254	Risk Ratio (M‐H, Random, 95% CI)	0.40 [0.09, 1.76]
1.8 Sedation (long‐term)	4	281	Risk Ratio (M‐H, Random, 95% CI)	0.51 [0.16, 1.68]