Table 1.

Result of the metaregression.

	Number of studies	Coefficient  (95% CI)	t	P	Tau2	I 2 Res  (%)	Adjusted  R 2 (%)
Urea baseline	10	−50.74 (−63.32, −38.16)	−9.30	<0.001	0.00	0.00	100.00