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. Author manuscript; available in PMC: 2016 Sep 7.
Published in final edited form as: Biometrics. 2016 Jan 12;72(3):897–906. doi: 10.1111/biom.12470

Table 3.

Simulation results for the settings with p = 10 and t = 20. Cox: censoring weights are estimated from a Cox PH model. Lasso-Cox1: censoring weights are estimated from a Cox PH model using the selected variables based on a Lasso Cox PH model. Lasso-Cox2: censoring weights are estimated directly from a Lasso Cox PH model.

ζ n 2
Δc^s1(SD)
Δc^s2(SD)
Δc^g1(SD)
Δc^g2(SD)
ctrue
0.3 50 Cox 0.088(0.074) 0.021(0.046) 0.055(0.095) 0.002(0.056) 0.858
Lasso-Cox1 0.051(0.093) 0.002(0.054)
Lasso-Cox2 0.102(0.082) 0.029(0.050)
100 Cox 0.082(0.046) 0.024(0.029) 0.034(0.064) 0.005(0.035)
Lasso-Cox1 0.029(0.062) 0.006(0.032)
Lasso-Cox2 0.097(0.052) 0.032(0.033)
500 Cox 0.077(0.020) 0.027(0.013) 0.016(0.031) 0.006(0.015)
Lasso-Cox1 0.013(0.031) 0.008(0.014)
Lasso-Cox2 0.092(0.022) 0.036(0.014)
0.8 50 Cox 0.026(0.034) 0.005(0.029) 0.013(0.036) 0.002(0.029) 0.846
Lasso-Cox1 0.009(0.033) 0.002(0.028)
Lasso-Cox2 0.040(0.048) 0.010(0.049)
100 Cox 0.024(0.023) 0.007(0.021) 0.004(0.022) 0.000(0.019)
Lasso-Cox1 0.004(0.023) 0.001(0.020)
Lasso-Cox2 0.036(0.028) 0.011(0.036)
500 Cox 0.022(0.010) 0.008(0.009) 0.002(0.010) 0.000(0.008)
Lasso-Cox1 0.003(0.010) 0.001(0.008)
Lasso-Cox2 0.033(0.011) 0.013(0.009)

Note that Δc^s1(SD) and Δc^s2(SD) are the same for Cox, Lasso-Cox1 and Lasso-Cox2 becasue they do not require the estimation of censoring weights.