. Author manuscript; available in PMC: 2018 Sep 1.

Published in final edited form as: Clin Pharmacol Ther. 2017 May 30;102(3):529–536. doi: 10.1002/cpt.667

Table 2.

Univariate and multivariate linear regression analysis from each study group

Efavirenz group
log₁₀ C_max	Univariate linear regression			Multivariate linear regression
log₁₀ C_max	P value	β value (95% CI)	r²	P value	β value (95% CI)	r²
Age (years)	0.049	−0.027 (−0.01,0.0)	0.199
CYP2B6 516G>T (rs3745274)	0.021	−0.209 (−0.4,0.0)	0.263	0.021	−0.209 (−0.4,0.0)	0.263
log₁₀ AUC_{0–24 weeks}	P value	β (pg/mL) (95% CI)	r²	P value	β (pg/mL) (95% CI)	r²
Age (years)	0.028	−0.022 (0.0,0.0)	0.242	0.039	−0.018 (−0.0,0.0)	0.739
CD4 (log₁₀cells/mm³)	0.085	0.520 (−0.1,1.1)	0.156
CYP2B6 516G>T (rs3745274)	<0.000	−0.216 (−0.3,−0.1)	0.512	0.023	−0.132 (−0.2,0.0)	0.739
CYP2B6 15582C>T (rs4803419)	0.058	−0.172 (−0.3,0.0)	0.186	0.021	−0.163 (−0.3,0.0)	0.756
Nevirapine Group
log₁₀ C_max	Univariate linear regression			Multivariate linear regression
log₁₀ C_max	P value	β value (95% CI)	r²	P value	β value (95% CI)	r²
Age (years)	0.056	0.015 (0.0,0.0)	0.189	0.044	0.013 (0.0,0.3)	0.569
Albumin concentration at baseline (g/L)	0.076	0.019 (0.0,0.0)	0.164
SHBG at baseline (log₁₀ pg/mL)	0.017	0.480 (0.1,0.9)	0.280	0.007	0.469 (0.0,0.8)	0.569
CYP2B6 516G>T (rs3745274)	0.115	0.098 (0.0,0.2)	0.133	0.034	0.103 (0.0,0.2)	0.569
T_max	P value	β value (95% CI)	r²	P value	β value (95% CI)	r²
Age (years)	0.043	−0.259 (−0.5,0.0)	0.209
Weight (log₁₀ kg)	0.029	−16.956 (−31.9,−0.2)	0.239	0.002	−15.910 (−24.9,−6.9)	0.771
CD4 (log₁₀ cells/mm³)	0.157	−3.489 (−8.5,1.5)	0.108
Albumin concentration at baseline (g/L)	0.001	−0.499 (−0.8,0.2)	0.446	0.003	−0.340 (−0.5,−0.1)	0.771
NR1I2 63396C>T (rs2472677)	0.013	2.000 (0.5,3.5)	0.300	0.003	1.623 (0.6,2.6)	0.771
log₁₀ C_min	P value	β value (95% CI)	r²	P value	β value (95% CI)	r²
Weight (log₁₀kg)	0.168	−0.751 (−1.8,0.3)	0.103
SHBG at baseline (log₁₀ nmol/L)	0.022	0.496 (0.1,0.9)	0.258	0.011	0.522 (0.1,0.9)	0.561
CYP2B6 516G>T (rs3745274)	0.118	0.104 (0.0,0.2)	0.130	0.048	0.115 (0.0,0.2)	0.561
log₁₀ AUC_{0–24 weeks}	P value	β value (95% CI)	r²	P value	β value (95% CI)	r²
CD4 (log₁₀cells/mm³)	0.034	−0.282 (−0.5,0.0)	0.227
SHBG at baseline (log₁₀ pg/mL)	0.008	0.465 (0.1,0.8)	0.333	0.004	0.484 (0.2,0.8)	0.457
CYP2B6 516G>T (rs3745274)	0.179	0.075 (0.0,0.0)	0.098

Univariate linear regression (P=≤0.2) completed, all statistically significant results then carried through to multivariate linear regression analysis (P=≤0.05). All statistically significant variables from multivariate linear regression shown in bold type.

β is the regression coefficient and represents incremental change in the log₁₀ LNG pharmacokinetic parameter per unit change in a patient characteristic (e.g. per kg body weight or per allele carried). So if β=0.5 an increase per unit in the patient characteristic results in the log₁₀ LNG pharmacokinetic parameter increasing by a factor of 0.5.