. 2022 Jul 13;44(6):729–737. doi: 10.1097/FTD.0000000000001006

TABLE 2.

Parameter Estimates of Final PK Model

Parameter	Description	Estimate	%RSE	Bootstrap Median (95% CI)
Structural model
$C L / F = θ_{1} \cdot {(\frac{A g e}{49})}^{θ_{2}} \cdot (P O D^{θ_{3}} i n e a r l y p h a s e) \cdot (P O D^{θ_{4}} i n l a t e p h a s e)$
$θ_{1, p r e o p}$	Oral clearance (CL/F) before surgery (L/h) in kidney transplant patients	21.9	12.2	22.3 (12.5,28.8)
$θ_{1, p o s t o p, k i d n e y}$	Baseline CL/F after surgery in kidney transplant patients (L/h)	20.5	5.9	20.3 (18.1,22.9)
$θ_{1. p o s t o p, l i v e r}$	Baseline CL/F after surgery in liver transplant patients (L/h)	12.9	17.9	12.7 (7.74,20.2)
$θ_{2}$	Age effect	−0.397	27.7	−0.443 (−0.767, −0.191)
$θ_{3, k i d n e y}$	POD effect in early period in kidney transplant patient	0.112	13.3	0.107 (0.0748, 0.138)
$θ_{3, l i v e r}$	POD effect in liver transplant patient	0.0557	63.2	0.0589 (0.00161, 0.195)
$θ_{4, k i d n e y}$	POD effect in late period in kidney transplant patient	−0.023	13.3	−0.0237 (−0.0506, −0.00148)
$V / F = θ_{5} \cdot {(\frac{W T}{62.4})}^{θ_{6}}$
$θ_{5}$	Apparent volume (L)	499	12.2	482 (355, 647)
$θ_{5}$	Body weight effect	1.30	34.6	1.26 (0.0756, 2.29)
$k_{a}$	Absorption rate constant	2.59	14.3	2.60 (1.96, 3.47)
$A L A G_{1}$	Lag time of first-order absorption	0.25 (fix)
Interindividual variability (CV%)
ω_CL/F	Interindividual variability of CL/F	43.4	6.4	50.8 (39.7, 67.5)
ω_V/F	Interindividual variability of V/F	84.2	11.9	89.6 (30.0, 118)
Correlation coefficients
ρ_CL/F-V/F	Correlation coefficients between CL/F and V/F	0.221	40.5	0.198 (0.0186, 0.281)
Residual error
σ_{add, 1}^_*	Additive error	0.0001 (fix)
σ_{prop, 1}^_*	Proportional error	0.244	3.6	0.244 (0.227, 0.262)
σ_{add, 2}^_*	Additive error	−2.77	13.7	−2.91 (−3.5, −2.1)
σ_{add, 3}^_*	Additive error	2.78	10.3	2.71 (2.34, 3.03)

Number refers to the hospital where data were collected (1: Seoul National University Hospital, 2: Inje University Busan Paik Hospital, 3: Chonnam National University Hospital).

PK, pharmacokinetics; POD, postoperative days; CI, confidential interval; CL, clearance; F, bioavailability; V, volume of distribution; WT, body weight.