TABLE 4.
PPK parameter estimates from the final model and bootstrap validation.
| Description | Parameter | Base model | Final model | Bootstrap a | Relative error (%) b | |||
|---|---|---|---|---|---|---|---|---|
| Estimate | RSE (%) | Estimate | RSE (%) | Median | 95% CI | |||
| CL/F (L/h) | θCL | 0.205 | 7.4 | 0.214 | 7.4 | 0.207 | 0.136–0.245 | −3.3 |
| V/F (L) | θV | 3.43 | 22.7 | 3.63 | 23.8 | 3.57 | 1.07–6.14 | −1.7 |
| Age on CL/F | θAge | — | — | 0.357 | 9.6 | 0.349 | 0.243–0.423 | −2.2 |
| ABCB1 rs3789243 AG on CL/F | θABCB1 AG | — | — | 0.953 | 4.7 | 0.955 | 0.872–1.06 | 0.2 |
| ABCB1 rs3789243 GG on CL/F | θABCB1 GG | — | — | 1.08 | 5.5 | 1.08 | 0.967–1.22 | 0 |
| IIV on CL/F (%) | ωCL | 0.302 | 10.9 | 0.169 | 13.0 | 0.167 | 0.106–0.42 | −1.2 |
| η-shrinkage (%) | ηshrinkage | 5.8 | — | 12.1 | — | — | — | — |
| RV (mg/L) | σadditive | 13.7 | 6.5 | 11.9 | 5.9 | 11.8 | 11.3–15.0 | −0.8 |
| ε-shrinkage (%) | εshrinkage | 12.9 | — | 11.1 | — | — | — | — |
CL/F, clearance; V/F, distribution volume; IIV, inter-individual variability; RV, residual variability; θ, factor describing the relationship between the covariate and the clearance; ω, coefficient variation of inter-individual variability; σ, coefficient variation of residual variability; RSE(%), relative standard error (standard error/estimate × 100%); 95%CI, 95% confidence interval.
a
995 of 1,000 bootstrap runs were successful and used to calculate the point estimates and 95%CI.
b
Relative error % = (Bootstrap median − estimate in final model)/estimate in final model × 100%.