Omitting	mean difference (MD)	95% confidence interval (CI)	P value	Heterogeneity I2
Tascioglu −2010	−3.1271	−7.8250; 1.5707	0.1920	59.3%
Loyola −2012	−5.1209	−9.0205; −1.2214	0.0101	56.5%
Gao −2016	−3.0351	−7.4206; 1.3504	0.1750	53.4%
Jia −2016	−3.4329	−9.3539; 2.4881	0.2558	65.1%
Kim −2019	−5.7568	−9.1161; −2.3974	0.0008	39.8%
Karakas −2020	−4.5866	−9.1615; −0.0117	0.0494	63.1%
Pooled estimate	−4.3474	−8.2954; −0.3993	0.0309	56.5%