Table 2.

Dosing algorithm for Caucasians in the multivariate linear regression model (outcome variable is log warfarin maintenance dose per day).^*

Variable†	N	Regression coefficient (95% CI)
Intercept	147	2.74 (2.38 to 3.10)
Age	147	−0.01 (−0.01 to 0.00)
VKORC1 1173 (CT=1)	74	−0.40 (−0.53 to −0.27)
VKORC1 1173 (TT=1)	13	−0.82 (−1.05 to −0.59)
CYP2C9 (any*2=1)	42	−0.21 (−0.36 to −0.07)
CYP2C9 (any*3=1)	18	−0.32 (−0.52 to −0.12)
BMI (less than 25=1)	50	−0.18 (−0.35 to −0.01)
BMI (25 to 30=1)	59	−0.19 (−0.35 to −0.03)
Number of medications that potentiate warfarin	147	−0.08 (−0.14 to −0.03)
Most drinks on one occasion	147	0.03 (0.00 to 0.05)
History of deep vein thrombosis (yes=1)	16	0.21 (0.01 to 0.41)
Gender (female=1)	43	−0.13 (−0.27 to 0.02)

^*Dose (mg/day) = exp[2.74 −(0.01 X age) −(0.40 X VKORC1 1173CT) −(0.82 X VKORC1 1173TT) −(0.21 X CYP2C9 any*2) −(0.32 X CYP2C9 any*3) −(0.18 X BMI <25) −(0.19 X BMI 25 to 30) −(0.08 X number of medications that potentiate warfarin) +(0.03 X most alcoholic drinks on one occasion) +(0.21 X history of deep vein thrombosis) −(0.13 X female)]

^†Age, number of medications that potentiate warfarin, and most drinks on one occasion were entered as linear terms in the model and dummy variables (0=absent, 1=present) for the other variables.