Table 4.

Performance of gene-based warfarin dosing algorithms alone and with selected VKORC1, CYP4F2 or CALU variants added as covariates

Algorithm	Original algorithm		VKORC1 g.698C > T added		VKORC1 g.2255C > T added*		VKORC1 g.3730G > A added†		CYP4F2*3 added		CYP4F2-rs2189784 added		CALU p.R4Q added
	R2	Adj. R2	Δ adj. R2	P value	Δ adj. R2	P value	Δ adj. R2	P value	Δ adj. R2	P value	Δ adj. R2	P value	Δ adj. R2	P value
Wu 2008 [31]	0.55	0.50	0	0.28	–	–	0	0.30	0	0.58	0	0.78	0	0.56
Gage 2008 [30]	0.54	0.51	0	0.41	0	0.60	0	0.21	0	0.70	0	0.88	0	0.63
Anderson 2007 [27]	0.52	0.50	−0.01	0.45	−0.01	0.63	0	0.13	−0.01	0.44	−0.01	0.72	0	0.28
Herman 2006 [34]	0.52	0.50	0	0.41	−0.01	0.92	–	–	−0.01	0.54	−0.01	0.83	0	0.39
Zhu 2007 [29]	0.51	0.49	0	0.50	0	0.40	0	0.09	0	0.37	−0.01	0.63	0	0.28
IWPC 2009 [33]	0.50	0.45	0	0.47	0	0.71	0	0.41	0	0.99	0	0.65	0	0.99
Tham 2006 [26]	0.48	0.46	0	0.32	0.01	0.05	0	0.32	−0.01	0.96	−0.01	0.59	0	0.45
Wadelius 2009 [32]	0.46	0.43	0	0.42	−0.01	0.91	0	0.25	0	0.65	−0.01	0.93	0	0.63
Wadelius 2005 [24]	0.46	0.42	−0.01	0.98	0	0.44	0	0.72	0	0.99	0	0.43	0	0.78
Sconce 2005 [23]	0.45	0.44	−0.01	0.45	−0.01	0.93	0	0.24	−0.01	0.54	−0.01	0.86	−0.01	0.53
Takahashi 2006 [25]	0.38	0.35	0	0.55	0.01	0.21	0	0.55	0	0.99	0	0.68	0	0.82
Miao 2007 [28]	0.37	0.35	−0.01	0.60	0	0.21	−0.01	0.62	−0.01	0.83	−0.01	0.58	−0.01	0.78

^*Wu et al. 2008 [31] included indicators for VKORC1 g.2255C > T.

^†Herman et al. 2006 [34] included indicators for VKORC1 g.3730G > A.

Adj., adjusted; IWPC, International Warfarin Pharmacogenetics Consortium.