Final multivariate regression model for predicting the weekly warfarin maintenance dose
| Predictor . | Coefficient . | SE . | P . | Univariate R2 . |
|---|---|---|---|---|
| Intercept | −10.77 | 4.44 | ||
| Height, cm | 0.28 | 0.028 | < .0001 | 0.481 |
| Number of VKORC1 variant allele(s) | −5.44 | 1.41 | .0003 | 0.182 |
| Target INR | ||||
| 2.2 | 0 | – | – | – |
| 2.5 | 7.83 | 2.08 | .0003 | 0.019 |
| 3.3 | 11.52 | 2.74 | < .0001 | 0.025 |
| Number of CYP2C9 variant allele(s) | −3.29 | 1.55 | .0370 | 0.020 |
| Predictor . | Coefficient . | SE . | P . | Univariate R2 . |
|---|---|---|---|---|
| Intercept | −10.77 | 4.44 | ||
| Height, cm | 0.28 | 0.028 | < .0001 | 0.481 |
| Number of VKORC1 variant allele(s) | −5.44 | 1.41 | .0003 | 0.182 |
| Target INR | ||||
| 2.2 | 0 | – | – | – |
| 2.5 | 7.83 | 2.08 | .0003 | 0.019 |
| 3.3 | 11.52 | 2.74 | < .0001 | 0.025 |
| Number of CYP2C9 variant allele(s) | −3.29 | 1.55 | .0370 | 0.020 |
Target INR was 2.2 in patients with total cavopulmonary connection; 2.5 in those with aortic valve replacement, dilated cardiomyopathy, coronary aneurysms after Kawasaki disease, or extracardiac diseases; and 3.3 in those with mitral valve replacement.
Dose (mg/wk) = −10.77 + 0.28 × height (cm) −5.44 × number of VKORC1 variant allele(s) + 7.83 (if target INR of 2.5) or 11.52 (if target INR of 3.3) −3.29 × number of CYP2C9 variant alleles.