. 2017 Jan 24;61(2):e01701-16. doi: 10.1128/AAC.01701-16

TABLE 4.

Coefficient and standardized estimates of joint predictors of drug plasma pharmacokinetics from multivariate analysis using MCP modeling

Drug	Parameter	Predictor	r²^a	P value for model significance	Parameter estimate (SE)	P value	Standardized estimate^b
Isoniazid	C_max	Dose (mg)	0.09	0.005	0.002 (0.001)	0.007	0.249
	C_max	NAT2 non-slow vs slow	0.09	0.005	0.177 (0.095)	0.063	0.171
	AUC_0–8	Dose (mg)	0.21	<0.001	0.030 (0.013)	0.020	0.201
		NAT2 non-slow vs slow	0.21	<0.001	8.351 (1.739)	<0.001	0.408
	CL/F	Dose (mg)	0.41	<0.001	0.005 (0.001)	<0.001	0.451
		NAT2 non-slow vs slow	0.41	<0.001	−0.650 (0.107)	<0.001	−0.447
Rifampin	C_max	Dose (mg)	0.12	<0.001	0.002 (0.001)	0.001	0.300
	C_max	TB/HIV vs TB	0.12	<0.001	−0.182 (0.107)	0.092	−0.153
	AUC_0–8	Dose (mg)	0.17	<0.001	0.042 (0.012)	0.001	0.312
		Male vs female			−4.234 (2.473)	0.090	−0.150
		TB/HIV vs TB			−5.364 (2.474)	0.032	−0.191
	CL/F	Dose (mg)	0.15	<0.001	0.002 (0.001)	<0.001	0.367
		Male vs female			0.178 (0.120)	0.141	0.131
		TB/HIV vs TB			0.195 (0.120)	0.108	0.144
Pyrazinamide	C_max	Dose (mg)	0.10	<0.001	0.001 (<0.001)	0.001	0.312
	AUC_0–8	Dose (mg)	0.17	<0.001	0.099 (0.022)	<0.001	0.391
	AUC_0–8	TB/HIV vs TB	0.17	<0.001	−10.638 (9.369)	0.259	−0.101
	CL/F	Dose (mg)	0.26	<0.001	0.002 (<0.001)	<0.001	0.509
	CL/F	TB/HIV vs TB	0.26	<0.001	0.195 (0.133)	0.144	0.124
Ethambutol	C_max	Dose (mg)	0.32	<0.001	0.002 (<0.001)	<0.001	0.439
		Male vs female			−0.154 (0.115)	0.181	−0.109
		TB/HIV vs TB			−0.396 (0.115)	0.001	−0.280
	AUC_0–8	Dose (mg)	0.32	<0.001	0.010 (0.002)	<0.001	0.439
		Male vs female			−1.009 (0.576)	0.083	−0.141
		TB/HIV vs TB			−2.005 (0.579)	0.001	−0.280
	CL/F	Dose (mg)	0.29	<0.001	0.002 (<0.001)	<0.001	0.491
		Male vs female			0.201 (0.106)	0.061	0.156
		TB/HIV vs TB			0.349 (0.106)	0.001	0.272

Proportion of the variance in PK parameters explained by selected models.

The standardized estimates are all in the same standardized units, so that the relative strength in predicting outcomes can be assessed by comparing them. For example, the standardized coefficient estimate of 0.312 for dose in predicting rifampin AUC_0–8 means that a one-standard-deviation increase in dose leads to a 0.312-standard-deviation increase in predicted rifampin AUC_0–8, with the other variables held constant. The predicting power of the predictors for rifampin AUC_0–8 can be ranked as dose > HIV infection status > sex.