Table 9.

Analysis of Variance for Cox Proportional Hazard Model Assessing the Association of Proposed 2-Tier Grading System and Patnaik Grading System on Survival^a

	Variable	Log Likelihood	χ2	P
Model 1	Null	−56.83
	Proposed grading systema	−37.71	38.24	< .001
	Patnaik grading systemb	−37.61	0.20	.66
Model 2	Null	−56.83
	Patnaik grading systemb	−44.88	23.90	< .001
	Proposed grading systema	−37.61	14.54	< .001

^adf = 1,

^bdf = 2.