Table 2 Power of analysis of primary endpoint under different assumptions for the design effect

ICC

0.01

0.02

0.05

0.08

0.01

0.02

0.05

0.08

0.01

0.02

0.05

0.08

Cluster size

5

5

5

5

10

10

10

10

15

15

15

15

Design effect

1.04

1.08

1.20

1.32

1.09

1.18

1.45

1.72

1.14

1.28

1.70

2.12

Power (1-β)

0.85

0.84

0.79

0.76

0.83

0.80

0.72

0.64

0.81

0.77

0.65

0.55