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. Author manuscript; available in PMC: 2012 Sep 1.
Published in final edited form as: Biometrics. 2011 Mar 1;67(3):1163–1170. doi: 10.1111/j.1541-0420.2011.01561.x

Table 2.

Powers and Type I Errors for 12-Month TLF

Total Sample Size 1000 1080 1200 1280 1480
nt 750 810 900 960 1110
nc 250 270 300 320 370

Frequentist SSD
z Test (Unpooled) Power 0.617 0.646 0.685 0.710 0.764
Score Test Power 0.672 0.699 0.736 0.758 0.807

Bayesian SSD
No Borrowing Power 0.648 0.676 0.718 0.738 0.800
a0 = (0, 0) Type I Error 0.049 0.048 0.048 0.050 0.044

Hierarchical Prior Power 0.796 0.820 0.841 0.863 0.894
(ξ0, η0) = (0.01, 0.01) Type I Error 0.044 0.045 0.044 0.049 0.048

Hierarchical Prior Power 0.839 0.860 0.882 0.900 0.922
(ξ0, η0) = (0.001, 0.001) Type I Error 0.038 0.042 0.039 0.040 0.041

Power Prior Power 0.840 0.856 0.884 0.892 0.923
Fixed a0 = (0.3, 0.3) Type I Error 0.030 0.027 0.028 0.030 0.032

Power Prior Power 0.843 0.878 0.897 0.902 0.914
Random a0 Type I Error 0.038 0.031 0.029 0.036 0.039