A meta-analysis of N-acetylcysteine in contrast-induced nephrotoxicity: unsupervised clustering to resolve heterogeneity

Table 2 Meta-regression of study and patient factors

	Characteristic	r*	p-value
Study-related	Publication date (months after first)	0.36	0.1
	Study size (number of patients)	0.14	0.54
	Jadad score (1–5)	0.07	0.75
	Total NAC dose (mg)	-0.26	0.25
Patient-related	Age (years)	-0.13	0.56
	Baseline Creatinine (mg/dl)	-0.01	0.96
	Diabetes mellitus (%)	-0.23	0.31
	Female (%)	0.1	0.72
	Contrast volume (ml)	-0.27	0.24
	CIN event rate in control group (%)	0.21	0.35

*A negative correlation coefficient implies more benefit as the tested independent variable increases.

ISSN: 1741-7015