TABLE 3.

Results from Cox regression simulation using B-splines to model nonlinearity in tumor volume

	P value	δβ	${\mathit{\Delta }}_{\beta }^{\text{marg}}$	Correlated
				P value	δβ	${\mathit{\Delta }}_{\beta }^{\text{marg}}$
psa	.001	4.20	4.23	.135	2.17	1.09
Tumor volume	.008	2.27	2.31	.006	3.93	4.49
X1	.490	−0.20	−0.20	.484	−0.21	−0.21
X2	.483	−0.20	−0.20	.489	−0.23	−0.23
X3	.490	−0.21	−0.21	.505	−0.25	−0.25

psa, Prostate-specific antigen.