Table 3.

Summary of attributes of the pharmacogenetic equation for warfarin dosing prediction in Puerto Ricans using the derivation cohort from the Veterans Affairs Caribbean Healthcare System (PR, USA).

Variables†	Partial regression coefficient	SE	Adjusted R2 after entry	Effect on warfarin dose (%)‡	p-value
VKORC1:
– VKAA	−0.463	0.066	0.245	−21	<0.0001
– VKGA	−0.153	0.042
CYP2C9	−0.174	0.034	0.340	−17	0.003
Age (years), per decade	−0.0086	0.002	0.404	−9	0.010
PE	−0.272	0.091	0.474	−27	0.015
Amiodarone§	−0.276	0.107	0.486	−28	0.030
Dose-adjusted INR¶	−0.569	0.055	0.678	−14	<0.0001

Constant value of the model equation is 2.602 (SE: 0.158).

^†Variables are listed in the order they were incorporated into the model using stepwise regression analysis.

^‡Effect on the estimates of the effective dose is calculated per number of variant alleles (CYP2C9 and VKORC1), per decade (age) and per 0.25-unit increase in the dose-adjusted INR response at day 3.

^§Patients who are taking amiodarone concomitantly.

^¶INR over dose at day 3.

INR: International Normalized Ratio; PE: Pulmonary embolism; SE: Standard error.