Comparison 1. Preventive versus postincision opioids for postoperative pain.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Early acute postoperative pain (within 6 hours postoperatively)	10	706	Mean Difference (IV, Random, 95% CI)	0.11 [‐0.32, 0.53]
2 Nausea and vomiting (long term)	3	121	Risk Ratio (M‐H, Random, 95% CI)	0.90 [0.58, 1.39]
3 Late acute postoperative pain (24 to 48 hours postoperatively)	9	668	Mean Difference (IV, Random, 95% CI)	‐0.06 [‐0.13, 0.01]
4 24‐hour morphine consumption (mg)	11	526	Mean Difference (IV, Random, 95% CI)	‐4.91 [‐9.39, ‐0.44]
5 Time to first analgesic request (minutes)	6	298	Mean Difference (IV, Random, 95% CI)	‐8.15 [‐19.45, 3.14]
6 Pruritus (long term)	3	383	Risk Ratio (M‐H, Random, 95% CI)	0.75 [0.40, 1.43]
7 Bradycardia (incidence)	2	112	Risk Ratio (M‐H, Random, 95% CI)	0.33 [0.01, 7.88]
8 Bradycardia (mean dose of chronotrope in mcg)	2	112	Mean Difference (IV, Random, 95% CI)	‐9.68 [‐28.65, 9.29]
9 Hypotension (incidence)	2	88	Risk Ratio (M‐H, Random, 95% CI)	1.08 [0.25, 4.73]