Table 3B. Results of the meta-regression performed to identify potential sources of heterogeneity.

Variance	Coefficient	Std. Err.	p - value	RDOR	[95% CI]
Sample	−0.613	0.8780	0.5029	0.54	(0.07; 3.95)
method	0.482	1.3205	0.7235	1.62	(0.08; 32.11)
object	−0.415	0.8626	0.6421	0.66	(0.09; 4.65)
quality	−1.054	0.8773	0.2601	0.35	(0.05; 2.54)
country	1.098	1.3648	0.4420	3.00	(0.14; 65.70)
size	−0.315	1.2322	0.8041	0.73	(0.04; 11.85)
year	0.161	0.8811	0.8594	1.17	(0.16; 8.62)
quality*	−1.376	0.4944	0.0139	0.25	(0.09; 0.72)

Abbreviations: Std.Er, standard error; CI, confidence interval. ^*after processing.