From: Designs for clinical trials with time-to-event outcomes based on stopping guidelines for lack of benefit
R ij
i= 1
i= 2
i= 3
i= 4
j = 1
1
0.715
0.569
0.512
j = 2
0.722
0.793
0.717
j = 3
0.579
0.802
0.904
j = 4
0.529
0.733
0.914