Zhang Y, et al. - The agreement between single- and dual- plasma sampling methods with a three-point plasma clearance of iohexol was compared in this analysis. For this investigation, 46 healthy volunteers and 124 chronic kidney disease (CKD) patients with varying degrees of renal dysfunction received 5 ml iohexol (300 mgI/ml) i.v. and plasma samples were drawn at 2-, 3- and 4-h post-injection. In patients with glomerular filtration rate (GFR) ≥ 60 ml/min/1.73 m², 4-h single-plasma sampling methods (SPSM) was advantageous in clinical practice. A prolonged sampling time was more reliable for patients with an expected GFR < 60 ml/min/1.73 m².