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. Author manuscript; available in PMC: 2015 Jan 1.
Published in final edited form as: J Am Stat Assoc. 2014 Mar 19;109(505):384–394. doi: 10.1080/01621459.2013.842488

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, Δ̂LMT𝕊(t), Z and T𝕊 information, Δ̂LMW(t), and the augmented estimator, Δ̂AUGW(t) 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)
Δ̂LMT𝕊(t)
Δ̂LMW(t)
Δ̂AUGW(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