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Table 1 Sample Size Required for 90% Power to Detect a Difference in Means or a Difference in Responder Rates

From: Responder analyses and the assessment of a clinically relevant treatment effect

μ

x0

Responder Rates

Per Group Sample

Per Group Sample

  

pX

pC

Size – Difference in Means

Size – Difference in Rates

0.2

0

54.0%

46.0%

526

827

0.2

1

18.4%

13.6%

526

1204

0.2

2

2.9%

1.8%

526

4053

0.5

0

59.9%

40.1%

84

133

0.5

1

22.7%

10.6%

84

197

0.5

2

4.0%

1.2%

84

689

1.0

0

69.1%

30.9%

21

34

1.0

1

30.9%

6.7%

21

53

1.0

2

6.7%

0.6%

21

200