Table 4.

Meta-regression analyseis of potential source of heterogeneity

Heterogeneity factors	Coefficient	SE	t	P	95 % CI
					LL	UL
Country	82.25	25.89	3.18	0.037	27.37	137.13
Ethnicity	78.35	27.13	3.08	0.025	26.15	120.65
Language	8.82	18.07	0.49	0.598	−29.49	47.12
Sample Size	−0.18	0.37	−0.49	0.234	−26.96	102.39

(Notes: SE = Standard Error; LL = Lower Limit; UL = Upper Limit)