Table 1.

Summary of model progression

Model description		Baseline contamination	CTM (h)	OFV	AIC
Base model
1	Allometric model on V1, V2, V3, CL, Q2, Q3	–	–	599	619
2	As model 1, 2 outliers from pilot excluded	–	–	583	603
3	As model 2, $\mathrm{TVV}1={\theta }_1\cdot {(\mathrm{AGE}∕8.88)}_8^{\theta }$	–	–	576	598
Contamination model
4	CTM = θ9 on CVL	1 parameter: fixed	0.486 ng/mL	557	583
5	CTM = θ9 · IPRED on CVL	1 parameter: proportional	0.192	529	555
6	CTM1 = θ9 · IPRED on CVL (no clearing) CTM2 = θ10 · IPRED on CVL (with clearing)	2 parameters: proportional	θ9 = 0.149 θ10 = 0.436	527	557
7	As model 5, CTM = (θ9 · exp(-Ke · TIME)) · IPRED on CVL	1 parameter: proportional, declines with time	0.193	516	544

AIC Akaike’s information criteria, CL clearance, CTM contamination factor, CVL central venous line, DV observed concentration, IPRED individual predictions, Ke rate constant for change in contamination factor, OFV objective function value, Q2 and Q3 inter-compartmental clearance, TVV1 typical population value of volume of central compartment, V1 volume of central compartment, V2 and V3 volume of peripheral compartment