Table 3.

Sensitivity analyses.

Strategies of Sensitivity Analyses	Risk Ratio or Mean Difference [95% CIs] (%)	Number of Studies Analysed	Difference of Results	Total Number of Subjects	Heterogeneity
					I 2	p-Value
Pain score (5 min)
Excluding low- or medium-quality studies	0.81 [−1.84, 3.46]	3	0.13 lower	322	98%	<0.00001
Using a fixed-effects model	1.69 [1.41–1.97]	5	0.75 higher	474	96%	<0.00001
Pain score (10 min)
Excluding low- or medium-quality studies	2.45 [2.11–2.79]	1	0.92 higher	152	NA	NA
Using a fixed-effects model	2.19 [1.88–2.50]	3	0.66 higher	304	85%	0.0001
Pain score (15 min)
Excluding low- or medium-quality studies	−0.12 [−1.37–1.14]	3	0.27 lower	354	86%	0.0008
Using a fixed-effects model	0.08 [−0.27–0.44]	5	0.07 lower	506	82%	0.0001
Pain score (20 min)
Excluding low- or medium-quality studies	0.95 [0.61, 1.29]	1	0.02 higher	152	NA	NA
Using a fixed-effects model	0.93 [0.63–1.24]	3	No change	304	0%	0.96
Pain score (25 min)
Using a fixed-effects model	0.24 [−0.71–1.19]	2	No change	152	0%	0.79
Pain score (30 min)
Excluding low- or medium-quality studies	0.16 [−0.46-0.78]	5	0.19 higher	1608	73%	0.005
Using a fixed-effects model	−0.13 [−0.37–0.11]	7	0.10 lower	1760	76%	0.0003
Pain score (60 min)
Excluding low- or medium-quality studies	−0.85 [−2.24–0.54]	2	0.45 lower	1186	91%	0.001
Using a fixed-effects model	−0.73 [−1.14, −0.32]	3	0.33 lower	1234	87%	0.0005
Rescue analgesic requirement
Excluding low- or medium-quality studies	1.66 [0.57–4.86]	3	No change	322	70%	0.04
Using a fixed-effects model	1.82 [1.06–3.12]	3	0.16 higher	322	70%	0.04

CIs: confidence intervals.