. Author manuscript; available in PMC: 2014 Jun 1.

Published in final edited form as: Pharmacogenomics J. 2013 Sep 10;14(3):223–228. doi: 10.1038/tpj.2013.34

Table 3.

Performance comparison of algorithms.

Algorithm	Warfarin dose (mean ±SD)	MAE (mean ±SE)	Pearson r	R²	Within 20%	Accurately Predicted
Therapeutic Dose	46.9 (17.2)	N/A	N/A	N/A	N/A	N/A
Novel African American	47.6 (11.4)	10.9 (0.92)	0.51^*	0.27^*	58.9%^a	10.9%^b
IWPC Pharmacogenomics	42.8 (9.1)^†	12.2 (0.98)	0.38^*	0.15^*	48.8%	2.3%^b
IWPC Clinical	30.6 (7.8)^†	17.9 (1.2)	0.41^*	0.16^*	26.4%^a	0%

Warfarin dose is in mg/week

MAE: mean absolute error

SD, standard deviation

SE, standard error

^†

Difference in mean dose is statistically significant from therapeutic dose.

Correlation is significant at the 0.01 level (2-tailed).

Difference is significant between novel algorithm and the IWPC clinical algorithm (p < 0.0001).

Difference is statistically significant, p = 0.02.

^a,b

P-values derived using McNemar’s test