Tamara van Donge

Chapter 7 134 around predicted concentrations and the individual weighted residuals are randomly scattered around zero. Predicted creatinine clearance versus Scr concentrations is illustrated in Figure 2 for different PNA. 0.25 0.50 0.75 0.5 1.0 1.5 2.0 Scr concentrations (mg/dl) Creatinine clearance (ml/min) Day 1 PNA Day 3 & 7 PNA Day 14 & 21 PNA Day 28, 35 & 42 PNA Figure 2: Individual predicted creatinine clearance versus predicted serum creatinine (Scr) concentrations, stratified by postnatal age (PNA). Model evaluation Good predictive performance with high accuracy (MPE [95% CI] -0.0028 mg/dl [-0.0075– 0.0019]) was obtained from the external analysis (Table 3). The relative MPE [95% CI] was equal to 0.85% [0.14–1.57] and good precision was observed as the relative RMSE [95% CI] amounted 12.75% [12.11–13.37].