Table 2. Pooled results of pain intensity.

Time	Subgroups	No of studies	No of patients	SMD [95% CI]	p-value	Heterogeneity (I2)
0 min	Overall	5	410	0.05 [-0.15, 0.25]	0.61	0
	Without antiemetic	2	99	-0.11 [-0.52, 0.30]	0.60	0
	With antiemetic	3	301	0.10 [-0.13, 0.32]	0.39	0
5 min	Overall	4	248	-0.45 [-0.71, -0.19]	< 0.05*	2
	Without antiemetic	2	99	-0.61 [-1.04, -0.19]	< 0.05*	0
	With antiemetic	2	149	-0.32 [-0.78, 0.14]	0.17	46
15 min	Overall	5	410	-0.41 [-0.72, -0.09]	< 0.05*	54
	Without antiemetic	2	99	-0.72 [-1.14, -0.29]	< 0.05*	0
	With antiemetic	3	311	-0.28 [-0.67, 0.10]	0.15	62
30 min	Overall	4	329	-0.19 [-0.61, 0.24]	0.39	66
	Without antiemetic	1	18	-0.47 [-1.43,0.49]	0.34	NA
	With antiemetic	3	311	-0.14 [-0.64, 0.35]	0.58	77

CI, confidence interval; NA, not applicable; SMD, standardized mean difference

*, statistically significant