Table 2.
Results from testing for a difference in survival at time t = 2 years between the two treatment groups using a Kaplan Meier estimator, Δ̂KM(t), the proposed estimator using Z information only, Δ̂Z(t), T𝕊 information only, , Z and T𝕊 information, , and the augmented estimator, with corresponding empirical standard error (ESE), average of the standard error estimates from the perturbation-resampling method (ASE), efficiency relative to ŜKM(t) with respect to MSE, and power.
Δ̂KM(t) | Δ̂Z(t) | |||||||
---|---|---|---|---|---|---|---|---|
Setting (i), no treatment difference | ||||||||
Estimate | −0.0002 | −0.0002 | −0.0004 | −0.0001 | 0.0003 | |||
ESE | 0.0323 | 0.0318 | 0.0316 | 0.0300 | 0.0282 | |||
ASE | 0.0326 | 0.0308 | 0.0309 | 0.0291 | 0.0267 | |||
REMSE | - | 1.12 | 1.12 | 1.26 | 1.49 | |||
α | 0.0415 | 0.0462 | 0.0544 | 0.0467 | 0.0538 | |||
Setting (ii), small treatment difference | ||||||||
Estimate | 0.0525 | 0.0519 | 0.0520 | 0.0523 | 0.0525 | |||
ESE | 0.0318 | 0.0312 | 0.0312 | 0.0292 | 0.0276 | |||
ASE | 0.0323 | 0.0305 | 0.0306 | 0.0287 | 0.0263 | |||
REMSE | - | 1.12 | 1.11 | 1.27 | 1.51 | |||
Power | 0.3740 | 0.4110 | 0.4060 | 0.4570 | 0.5200 | |||
Setting (iii), large treatment difference | ||||||||
Estimate | 0.0954 | 0.0942 | 0.0947 | 0.0952 | 0.0952 | |||
ESE | 0.0317 | 0.0312 | 0.0310 | 0.0288 | 0.0270 | |||
ASE | 0.0320 | 0.0301 | 0.0303 | 0.0283 | 0.0259 | |||
REMSE | - | 1.13 | 1.11 | 1.27 | 1.53 | |||
Power | 0.8460 | 0.8690 | 0.8650 | 0.9090 | 0.9410 |