Table 2.

Model assessment and comparison: median mean squared error of the estimated covariate effects. Under comparison are the Cox model fittings based on the ICPW estimate, the DSIR estimate, the original predictors, and the spline basis of the original predictors, respectively.

Model	ε	Method	n = 400	n = 800	n = 1200
(7)	PH	Cox-ICPW	0.656	0.619	0.603
		Cox-DSIR	0.797	0.643	0.591
		Cox-Linear	1.200	1.293	1.351
		Cox-Spline	0.864	0.926	0.990
(7)	PO	Cox-ICPW	0.888	0.865	0.858
		Cox-DSIR	1.091	0.978	0.936
		Cox-Linear	1.321	1.369	1.435
		Cox-Spline	1.046	1.124	1.175
(8)	PH	Cox-ICPW	0.511	0.403	0.353
		Cox-DSIR	1.052	1.017	0.977
		Cox-Linear	0.864	0.890	0.932
		Cox-Spline	0.755	0.796	0.818
(8)	PO	Cox-ICPW	0.624	0.548	0.523
		Cox-DSIR	1.122	1.104	1.131
		Cox-Linear	0.911	0.938	0.975
		Cox-Spline	0.816	0.881	0.900