Average predicted dose and measures of model fit by racial groups with the IWPC algorithm
| . | Average predicted dose, mg/wk . | Median predicted dose, mg/wk . | P* . | MAE . | SE of MAE . | IWPC algorithm R2, % . |
|---|---|---|---|---|---|---|
| Asians | 24.01 | 21.97 | 7.41 | 0.20 | 23.94 | |
| Blacks | 40.14 | 39.74 | < .001 | 11.63 | 0.42 | 24.77 |
| Whites | 32.67 | 32.25 | 9.25 | 0.61 | 40.03 |
| . | Average predicted dose, mg/wk . | Median predicted dose, mg/wk . | P* . | MAE . | SE of MAE . | IWPC algorithm R2, % . |
|---|---|---|---|---|---|---|
| Asians | 24.01 | 21.97 | 7.41 | 0.20 | 23.94 | |
| Blacks | 40.14 | 39.74 | < .001 | 11.63 | 0.42 | 24.77 |
| Whites | 32.67 | 32.25 | 9.25 | 0.61 | 40.03 |
The International Warfarin Pharmacogenetics Consortium (IWPC) algorithm adjusts for the influence of VKORC1 −1639G>A, CYP2C9 genotype, age, height, weight, CYP2C9 enzyme inducer status, and amiodarone status on warfarin dose. Model parameters are estimated on the square root of warfarin dose, and the resulting R2 value is calculated by squaring the correlation between the retransformed predicted dose and observed dose.
MAE indicates mean absolute error; and SE, standard error.
P value from a Kruskal-Wallis test comparing predicted dose with racial group.