Table 3.

Summary of meta-analysis result

Vs. no-scalp block	All studies		I2	Preoperative		I2	Postoperative		I2
Subgroup	n	Effect size (95% CI)		n	Effect size (95% CI)		n	Effect size (95% CI)
Pain intensity after surgery
Very early period	7 (371)	−1.37 [−2.23, −0.50]	70%	4 (175)	−1.40 [−2.59, −0.21]	57%	3 (196)	−1.27 [−2.72, 0.17]	76%
Early period	9 (501)	−1.16 [−2.09, −0.24]	57%	5 (265)	−1.11 [−2.36, 0.15]	63%	4 (236)	−1.15 [−2.97, 0.66]	56%
Intermediate	7 (431)	−0.44 [−1.03, 0.15]	43%	3 (195)	−0.12 [−0.62, 0.37]	17%	4 (236)	−1.03 [−1.77, −0.29]	0%
Late period	7 (396)	−0.50 [−1.06, 007]	25%	4 (235)	−0.43 [−0.71, −0.15]	0%	3 (161)	−1.24 [−2.91, 0.43]	57%
Very late period	7 (431)	−0.54 [−1.37, 0.29]	77%	3 (195)	−0.50 [−1.79, 0.78]	78%	4 (236)	−0.62 [−1.94, 0.70]	77%
24 h total opioid consumption	7 (346)	−0.36 [−0.76, 0.04]	68%	3 (135)	−0.61 [−1.24, 0.01]	65%	4 (211)	−0.18 [−0.67, 0.31]	66%
Vs. placebo	All studies		I2	Preoperative		I2	Postoperative		I2
Subgroup	n	Effect size (95% CI)		n	Effect size (95% CI)		n	Effect size (95% CI)
Pain intensity after surgery
Very early period	5 (241)	−1.39 [−2.88, 0.11]	87%	3 (120)	−1.73 [−3.37, −0.09]	76%	2 (121)	−0.56 [−1.50, 0.38]	NA
Early period	7 (371)	−1.33 [−2.53, −0.13]	74%	4 (210)	−1.38 [−3.12, 0.35]	80%	3 (161)	−1.15 [−2.97, 0.66]	56%
Intermediate	6 (341)	−0.09 [−0.61, 0.44]	14%	3 (180)	0.06 [−0.39, 0.51]	0%	3 (161)	−0.77 [−1.86, 0.33]	1%
Late period	6 (341)	−0.53 [−1.23, 0.17]	39%	3 (180)	−0.33 [−0.78, 0.12]	0%	3 (161)	−1.24 [−2.91, 0.43]	57%
Very late period	6 (341)	−0.22 [−1.01, 0.56]	67%	3 (180)	−0.37 [−1.35, 0.60]	60%	3 (161)	−0.19 [−1.47, 1.10]	67%
24 h total opioid consumption	6 (281)	−0.53 [−1.07, 0.02]	78%	3 (120)	−0.80 [−1.74, 0.14]	81%	3 (161)	−0.28 [−0.98, 0.42]	77%