Supplementary Material for: Does Iodinated Contrast Affect Residual Renal Function in Dialysis Patients? A Systematic Review and Meta-Analysis

<b><i>Background:</i></b> It is important for medical practitioners to be aware of the effect of iodinated contrast media on the residual renal function (RRF) of dialysis patients who require diagnostic or therapeutic imaging procedures. Preservation of RRF is important given that it is a robust predictor of higher survival. However, the absence of any effect would allow for easier diagnostic or therapeutic imaging tests to be performed. <b><i>Objective:</i></b> This systematic review with meta-analysis will quantify the effect of intravascular administration of iodinated contrast on the residual function of adult dialysis patients. <b><i>Study Design:</i></b> The selection criteria included adult (age ≥ 18 years) populations undergoing dialysis, who have been administered an intravascular contrast. The primary outcome was the measurement of residual function. Secondary outcomes were disease progression from peritoneal dialysis to hemodialysis, hospitalization following contrast administration, and all-cause mortality. <b><i>Results:</i></b> Nine studies including 434 patients met the inclusion criteria. A meta-analysis was performed on 7 trials with complete quantitative data. The weighted difference in means was −0.16 mL/min (95% confidence interval −0.66 to 0.34 mL/min; <i>p</i> = 0.53), suggesting a small reduction in residual function following contrast administration. Significant heterogeneity in the data was observed, with a Cochran <i>Q</i> of 35.83 and an <i>I</i>² of 83.25 (<i>p</i> &lt; 0.0001). Subgroup analysis of retrospective versus prospective study design resolved heterogeneity. Few data were reported for clinical outcomes. <b><i>Limitations:</i></b> Small sample size of included studies. <b><i>Conclusion:</i></b> Intravascularly administered contrast media may not result in a significant reduction of residual function in dialysis patients.