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. Author manuscript; available in PMC: 2010 Apr 21.
Published in final edited form as: Stat Sin. 2010;20:661–674.

Table 2.

Simulation results for accelerated failure time cure model.

Case I (γ01 = 0.5) Proposed ZP
Parameters Bias SD SE CP Bias SD RE
extreme value error
β0 0.017 0.220 0.220 0.938 0.015 0.197 1.247
γ01 0.020 0.322 0.335 0.960 0.012 0.305 1.112
γ02 0.026 0.466 0.479 0.942 0.030 0.452 1.064
logistic error
β0 0.018 0.138 0.158 0.964 0.013 0.154 0.801
γ01 0.012 0.314 0.322 0.960 0.016 0.316 0.988
γ02 0.023 0.462 0.465 0.950 0.021 0.470 0.965
normal error
β0 0.031 0.176 0.182 0.948 0.004 0.190 0.859
γ01 0.028 0.321 0.317 0.958 0.009 0.321 0.999
γ02 0.003 0.483 0.457 0.940 0.032 0.471 1.052
Case II (γ01 = 1.0) Proposed ZP
extreme value error
β0 0.018 0.178 0.202 0.962 0.005 0.179 0.992
γ01 0.035 0.375 0.369 0.944 0.031 0.341 1.208
γ02 0.014 0.542 0.518 0.938 −0.008 0.503 1.163
logistic error
β0 0.015 0.127 0.142 0.970 0.007 0.143 0.790
γ01 0.035 0.344 0.356 0.966 0.037 0.349 0.971
γ02 −0.002 0.521 0.498 0.934 −0.008 0.536 0.946
normal error
β0 0.012 0.145 0.162 0.962 0.017 0.160 0.820
γ01 0.041 0.366 0.355 0.958 0.036 0.370 0.980
γ02 0.040 0.534 0.502 0.940 0.040 0.529 1.018
†

SD, sample standard deviation of parameter estimates; SE, mean of estimated standard errors; CP, coverage probability; RE, relative efficiency of Zhang and Peng’s estimator (ZP) compared with the proposed estimator (Proposed).