Table 2.
Parameter estimates of the base model, the covariate model and the 1000 bootstrap runs [median and 95% confidence interval (CI)]
| Parameter | Base model | Covariate model | 1000 bootstrap replicates Median (95% CI) |
|---|---|---|---|
| Objective function value | 636.194 | 531.507 | 513.29 (355.93, 702.08) |
| Fixed parameters | |||
| CL (l h−1) | 2.98 | 6.37† | 6.26† (5.37, 6.98) |
| Vc (l) | 8.22 | 18.70† | 18.60† (16.00, 20.56) |
| Q (l h−1) | 0.12 | 0.39 | 0.40 (0.25, 0.79) |
| Vper (l) | 9.93 | 1.32 | 1.57 (1.00, 4.90) |
| tlag (h) | 0.39 | 0.40 | 0.40 (0, 0.60) |
| Dc (h) | 0.5‡ | 0.5‡ | 0.5‡ |
| Random parameters (CV %) | |||
| BSV CL | 55.23 | 11.70 | 11.45 (6.74, 15.94) |
| BSV Vc | 61.97 | 11.66 | 10.63 (3.19, 18.80) |
| BSV Vper | 182.76 | 41.95 | 53.29 (17.43, 109.20) |
| BOV CL | 6.44 | 6.47 | 6.60 (3.06, 8.98) |
| Correlations between BSVs | |||
| R (CL, Vc) | 0.98 | 0.73 | 0.74 (0.34, 1.04) |
| R (CL, Vper) | 0.39 | 0.49 | 0.97 (−1.00, 1,01) |
| R (Vc, Vper) | 0.52 | 0.27 | 0.52 (−0.98, 1.00) |
| Residual variability (CV %) | 18.65 | 19.00 | 18.55 (15.42, 21.91) |
The typical value of clearance and volume refer to a patient with a total body weight of 70 kg for comparison with adult values. Typical value = Typical parameter estimate × (total body weight/70)∧f, f = 3/4 for clearance, f = 1 for volume.
Fixed. CL, Typical clearance from central compartment; Vc, typical volume of central compartment; Q, typical intercompartmental clearance; Vper, typical volume of peripheral compartment; tlag, typical lag-time between time of hanging infusion and drug entering the patient's vein; Dc, duration of infusion into the central compartment; BSV, between-subject variability; BOV, between-occasion variability; R, correlation coefficient between BSVs.