TABLE 2.

Change in objective function value by univariate and multivariate inclusion of covariates into base population pharmacokinetic model

Covariatea	Univariate analysis		Multivariate analysisb
	Δ Objective function	Univariate estimate	Δ Objective function	Retained in model
CL/F
CovPREG	−5.376	1.18	0.707	No
(GA/20)Cov	−3.986	0.25	−2.114	No
(Age/31)Cov	−6.119	−0.33	−1.977	No
(SCR/0.6)Cov	−16.174	−0.7	−16.699	Yes
(ALB/3.6)Cov	−5.051	−0.43	−2.343	No
COVRTV	−2.007	0.932	ND	NA
Vss/F
CovPREG	−6.474	1.3	−0.019	No
(GA/20)Cov	−5.726	0.48	−2.593	No
(Age/31)Cov	−5.849	−0.42	−2.245	No
(SCR/0.6)Cov	−14.627	1.04	−1.913	No
(ALB/3.6)Cov	−7.401	−0.89	−2.195	No
COVRTV	−1.647	1.02	ND	NA

^aCov^PREG, pregnancy status; (GA/20)^Cov, gestational age; (age/31)^Cov, age; (SCr/0.6)^Cov, serum creatinine; (ALB/3.6)^Cov, serum albumin; COV^RTV, ritonavir.

^bND, not determined; NA, not applicable.