compared low-dose atorvastatin plus probucol with high-dose atorvastatin plus probucol as well as with high-dose atorvastatin. No significant difference in CIN incidence was found between the groups 48 hours after the procedure. Li, 2014147 compared atorvastatin with atorvastatin plus probucol. No significant difference in CIN was reported between groups (Appendix E, Evidence Table E-20). Three studies compared either different dosages of the same statin143,149 or different statins.148 Jo, 2014149 found no significant difference between high-dose and low-dose atorvastatin in preventing CIN. Kaya, 2013148 found no significant difference between atorvastatin and rosuvastatin in preventing CIN. Xinwei, 2009143 found a significantly lower incidence of CIN in patients receiving high-dose simvastatin when compared with low-dose (Appendix E, Evidence Table E-20). One observational study reported on statins versus IV saline and found a significant decrease in CIN in the group receiving statins.151 The results were similar to those reported in the RCTs comparing statins with IV saline. Four articles published in Chinese and one in Arabic were reviewed to determine if findings published in non-English language journals were different than those published in Englishlanguage journals. Three studies compared statins with IV saline and found significantly significant reductions in CIN in the statin intervention group159,160 or higher estimated glomerular filtration rate in the statin group (statistical significance not reported).161 These results were generally consistent with the English-language RCTs comparing statins with IV saline. One study compared low-dose statins with high-dose statins and found no significantly significant difference between groups.162 Another compared rosuvastatin plus furosemide with furosemide and found no significant difference in CIN incidence between groups.163 Other Outcomes Secondary outcome reporting was not consistent across studies. Need for renal replacement therapy was reported in three comparing statins to IV saline, 144,145,156 and three comparing statins plus N-acetylcysteine to N-acetylcysteine,137,142,146 two comparing statins by dose of administration, 145,149 one comparing different statins.157 One study comparing statins157 and one comparing statin to IV saline reported on mortality.145 Three comparing statins plus N- 36 acetylcysteine to N-acetylcysteine, and one comparing statins by dose of administration149 also reported on mortality. Only p-values were reported for need for renal replacement therapy and mortality and none reached a significance of p less than 0.05. Two studies reported on length of stay or hospitalization, both of which compared statins to IV saline.139,144 One study showed no difference between groups while the other, Patti et al., 2011139 showed a statistically significant difference (p=0.007) favoring the use of statins. Cardiac events were reported in five studies, two for statins versus IV saline,145,157 two for statins plus N-acetylcysteine versus Nacetylcysteine,146,156 and one compared statins by dose.149 Statistical significance was reported only in the set of three studies comparing statins to IV saline. Two of these studies reported no statistically significant difference between groups,146,164 and the other reported a statistically significant difference (p=0.02) in favor of statins.145 Two studies comparing statins to IV saline reported on hospital length of stay reporting no comparisons between groups.139,144 The strength of evidence was insufficient regarding whether or not statins had an impact on any of these secondary outcomes (Table 6; Appendix E, Evidence Table E-21; see Appendixes F and G for study limitations). No clinically important or statistically significant differences were seen in the need for dialysis; very few events were reported.137,142,144-146,149,150,156,157 Five studies reported cardiac outcomes145,146,149,156,157 and did not report consistently across outcomes. Of the six studies that reported mortality by intervention group, none showed a statistically significant or clinically important difference; the strength of evidence was insufficient, however, because very few deaths were reported, with results that were too imprecise and inconsistent.137,142,145,146,149,157 The strength of evidence was insufficient to determine if statins were effective at reducing length of hospitalization (Table 6; Appendix E, Evidence Table E-21; see Appendix G for study limitations).139,144 Adverse events were reported in five studies. We were not able to draw any conclusions as to whether or not the incidence of adverse events differed between statins and IV fluids (Appendix E, Evidence Table E-22).143 37 Figure 10. Meta-analysis of statins plus IV fluids versus IV fluids with or without placebo for the prevention of contrast-induced nephropathy in patients receiving intra-arterial contrast %=percent; CI=confidence interval; CIN=contrast induced nephropathy; CKD=chronic kidney disease; IV=intravenous; N=sample size; p=p-value; RR=risk ratio 38 Figure 11. Meta-analysis of statins plus N-acetylcysteine plus IV fluids versus N-acetylcysteine plus IV fluids with or without placebo for the prevention of contrast-induced nephropathy in patients receiving intra-arterial contrast %=percent; CI=confidence interval; CIN=contrast induced