Table 3.

Structural and random-effects parameter estimates for the full covariate model

Parameter	Estimate	RSE %a	Asymptotic 95% CI	Shrinkage (%)b
Clearance CL [L/h]	65	5.2	58–71	–
Central volume V1 [L]	118	12	91–150	–
Peripheral volume V2 [L]	1030	3.9	950–1100	–
Intercompartmental clearance Q [L/h]	295	3.5	270–320	–
IIV on CL [var]	0.066	6.5	0.049–0.083	8.7
cov (CL, V1)	0.060	12.0	0.031–0.089	–
cov (CL, Q)	0.054	16.0	0.021–0.087	–
cov (CL, V2)	0.041	7.3	0.029–0.052	–
IIV on V1 [var]	0.32	7.1	0.24–0.42	8.1
cov (V1, Q)	0.25	7.7	0.18–0.33	–
cov (V1, V2)	0.081	9.0	0.052–0.11	–
IIV on Q [var]	0.24	9.2	0.16–0.33	5.4
cov (Q, V2)	0.090	16.0	0.021–0.087	–
IIV on V2 [var]	0.047	7.9	0.033–0.062	6.8
Proportional residual error [sd]	0.22	4.6	0.2–0.24	–
Additive residual error [ng/mL]	1.73	19.0	1.1–2.4	–

CI confidence interval, CL clearance, var variance, cov covariance, sd standard deviation, IIV inter-individual variability, Q intercompartmental clearance, RSE relative standard error, V1 central volume of distribution, V2 peripheral volume of distribution

^aObtained by NONMEM covariance step. The relative standard errors for individual variability parameters are reported on the approximate standard deviation scale (standard error/variance estimate)/2

^bThe epsilon shrinkage was estimated to 10%