Table 4.

GRADE summary of findings.

Outcome	Study design (number of participants)	Risk of bias	Inconsistency	Indirectness	Imprecision (ES (95%CI))	Publication bias	Other	Quality of evidence
Creatinine	11 RCTs (n = 588)	Most information is from studies at low or unclear risk of bias	I 2 = 90.6%, P < 0.001	One point	0.04 (−0.01 to 0.09)	Begg's test: P=0.639, Egger's test: P=0.867	No	Very low
Blood urea nitrogen	10 RCTs (n = 499)	Most information is from studies at low or unclear risk of bias	I 2 = 49.6%, P=0.037	One point	−0.69 (−1.36 to −0.01)	Begg's test: P=0.655, Egger's test: P=0.543	No	Low

GRADE working group grades of evidence. High quality: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.