Table 4.

Meta-regression analysis of variables predicting serum and plasma levels of IL-4.

Factors	Sample	Coefficient	Standard error	95% CI	Adjusted R2	P
Ethnicity	Serum	0.186	0.566	−0.966 to 1.339	−0.029	.774
	Plasma	−0.195	0.548	−1.400 to 1.011	−0.086	.729
Study design	Serum	−0.662	0.428	−1.533 to 0.209	0.041	.123
	Plasma	0.217	0.615	−1.135 to 1.570	−0.087	.73
Assay approach	Serum	0.609	1.067	−1.564 to 2.783	−0.023	.572
	Plasma	−0.84	1.386	−3.890 to 2.211	−0.061	.557
Infection site	Serum	−0.515	0.968	−2.486 to 1.456	−0.025	.598
	Plasma	−0.969	1.374	−3.993 to 2.055	−0.048	.495
Drug resistance	Serum	−0.141	0.766	−1.702 to 1.420	−0.033	.855
	Plasma	NA	NA	NA	NA	NA
Infection status	Serum	−1.54	0.809	−3.187 to 0.107	0.078	.066
	Plasma	−1.225	1.139	−3.731 to 1.281	0.015	.305

CI = confidence interval, IL-4 = interleukin-4, NA = not applicable.