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Table 5 Optimal two-stage parameters for designs that minimize either the ETSL (top line) or the EDA (bottom line) for testing H0: S(1) ≤ .35. Power is specified for S(1) = .5.#

From: Design of Phase II cancer trials evaluating survival probabilities

α

1 - β

DA/x*

t 1

C 1

C 2

I 1/Imax

EDA

MDA

ETSL

MTSL

.1

.9

1.50

1.01

.488

1.154

.49

1.05

1.15

.76

1.09

   

.81

-.489

1.257

.32

.96

1.03

.85

1.02

  

1.75

.93

.457

1.159

.48

1.00

1.15

.76

1.10

   

.76

-.291

1.245

.34

.94

1.05

.82

1.03

  

2

.87

.434

1.163

.47

.96

1.15

.75

1.10

   

.72

-.179

1.237

.36

.92

1.06

.80

1.04

  

3

.74

.375

1.172

.46

.88

1.15

.75

1.11

   

.63

.004

1.220

.38

.86

1.09

.77

1.07

  

4

.67

.346

1.176

.45

.84

1.15

.75

1.12

   

.59

.073

1.212

.39

.83

1.10

.76

1.08

.05

.95

1.50

.99

.680

1.536

.46

1.03

1.17

.72

1.10

   

.81

-.274

1.622

.32

.95

1.04

.81

1.02

  

1.75

.91

.648

1.541

.46

.98

1.16

.72

1.10

   

.75

-.084

1.612

.34

.92

1.06

.78

1.04

  

2

.85

.624

1.545

.45

.94

1.16

.71

1.11

   

.72

.024

1.605

.35

.89

1.07

.76

1.05

  

3

.72

.563

1.553

.44

.85

1.16

.71

1.12

   

.63

.202

1.591

.38

.83

1.10

.72

1.08

  

4

.66

.531

1.557

.44

.80

1.15

.70

1.12

   

.59

.266

1.586

.39

.79

1.11

.71

1.09

  1. # DA is the fixed sample duration of accrual; x* is the survival time of interest; t 1 is the time of the first interim review; C 1 and C 2 are the cutpoints for acceptance at the first stage and rejection at the second stage; I1 and Imax are the information available at the interim and final reviews; EDA and MDA are the expected and maximum duration of accrual relative to the single stage values; and ETSL and MTSL are the expected and maximum total study length relative to the single stage values. Expected values are calculated under the null hypothesis.
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BMC Medical Research Methodology

ISSN: 1471-2288

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