Zinc supplementation as an adjunct to standard therapy in childhood nephrotic syndrome - a systematic review

Table 3 Zinc for nephrotic syndrome (frequent relapses/steroid dependent)

	Patient or population: Patients with nephrotic syndrome
	Settings: Hospital setting
	Intervention: Zinc
Outcomes	Illustrative comparative risks4 (95%CI)		Relative effect (95%CI)	No. of participants (studies)	Quality of the evidence (GRADE)
	Assumed risk	Corresponding risk
	Control	Zinc
Frequency of relapses in 12 mo Follow-up: 12 mo	The mean frequency of relapses in 12 mo in the control groups was 17%	The mean frequency of relapses in 12 mo in the intervention groups was 0.17 lower (0.39 lower to 0.04 higher)		103 (2 studies)	Very low1,2,3
Frequency of relapses in 6 mo	The mean frequency of relapses in 6 mo in the control groups was 16%	The mean frequency of relapses in 6 mo in the intervention groups was 0.16 lower (0.6 lower to 0.3 higher)		50 (2 studies)	Very low1,2
Sustained remission/no relapse Follow-up: 12 mo	426 per 1000	605 per 1000 (422 to 873)	RR = 1.42 (0.99 to 2.05)	103 (2 studies)	Very low1,2,3
Proportion of infection episodes associated with relapse Follow-up: 12 mo	The mean proportion of infection episodes associated with relapse in the control groups was 17%	The mean proportion of infection episodes associated with relapse in the intervention groups was 0.17 lower (0 to 0 higher)		30 (1 study)	Very low1,2

¹Single trial;

²Small sample size;

³Allocation concealment not clear in one study;

⁴The basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95%CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95%CI). CI: Confidence interval; RR: Risk ratio; GRADE: Working Group grades of evidence; high quality: Further research is very unlikely to change our confidence in the estimate of effect; moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate; low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; very low quality: We are very uncertain about the estimate.