(A) Cystatin C (CyC) changes expressed as percentage of baseline for the recombinant human erythropoietin (rHuEPO) group (solid dots) and placebo (open dots) with 95% CI. (B) Relative differences between cystatin C levels for the groups (triangles) with 95% CI. Gray area in B reflects a ±15% change in the primary endpoint. Days 1–4 = days after surgery.