Table 2. Subgroup analyses for the pooled results of differences in serum IL-6 levels between SLE patients and healthy controls.

Variables	No. of studies	Pooled SMD (95% CI)	p-value	Heterogeneity
				I2 (%)	p-value
[1] Age
Adult	10	2.257 (1.054-3.46)	<0.01	97.5	<0.01
Child	3	1.861 (0.499-3.224)	<0.01	94.4	<0.01
[2] Region
Non-Asia	6	0.757 (0.24-1.275)	<0.01	81.7	<0.01
Asia	7	3.508 (1.662-5.354)	<0.01	98.3	<0.01
[3] Measuring methods
ELISA	9	2.914 (1.37-4.458)	<0.01	88.6	<0.01
Other methods	4	0.691 (0.181-1.201)	<0.01	37.5	0.2