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Table 5 Comparison of the non-stratified and stratified log-rank type test for different effect sizes: power

From: On comparison of net survival curves

 

62% events due to ex. haz.

93% events due to ex. haz.

 

LRt

LRt-str

LRt

LRt-str

X∈D, bal (sex); S∉D, bal, bin, ef 0

0.505

0.505

0.870

0.870

X∈D, bal (sex); S∉D, bal, bin, ef 2x

0.502

0.519

0.863

0.880

X∈D, bal (sex); S∉D, bal, bin, ef 5x

0.465

0.559

0.778

0.894

X∈D, bal (sex); S∉D, bal, 10str, ef 0

0.495

0.496

0.879

0.875

X∈D, bal (sex); S∉D, bal, 10str, ef 2x

0.486

0.499

0.862

0.878

X∈D, bal (sex); S∉D, bal, 10str, ef 5x

0.472

0.559

0.772

0.895

  1. Methods included: non-stratified (LRt) and stratified log-rank type test (LRt-str). (bal = balanced variable, i.e., the groups occur with equal probabilities; bin= binary variable; 10 str = 10 strata; ef= variable’s effect). X is the categorical covariate of interest, S the stratification covariate, D denotes the demographic variables
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BMC Medical Research Methodology

ISSN: 1471-2288

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