Bioequivalence and Bioavailability Forum • Simul'ants in my pants

Simul'ants in my pants [Two-Stage / GS Designs]

posted by d_labes – Berlin, Germany, 2011-02-08 10:07 (5619 d 06:14 ago) – Posting: # 6579
Views: 31,727

Dear Helmut!

First I'm very glad that I helped you to gnosis :-D

❝ Potvin's simulations were done with 0.95; is it that simple to use e.g. 0.90 instead?

Here the simul'ants answer:
Datasets simulated with CV=32%, GMR=1.08

Results taken Potvin literally (i.e. GMR=0.95 in power calculations and sample size adaption):

               n_total

  stage 1  -----------------

  n1 power mean 5%  med. 95% power alpha

  12 0.040 52.6 18 – 50 – 94 0.672 0.042

  24 0.275 47.2 24 – 48 – 80 0.711 0.048

  36 0.498 45.8 36 – 36 – 72 0.718 0.043

  44 0.597 48.8 44 – 44 – 68 0.718 0.037

Results with GMR=0.95 always replaced with 1.08:

               n_total

  stage 1  -----------------

  n1 power mean 5%  med. 95%  power alpha

  12 0.040 70.4 24 – 66 – 128 0.778 0.042

  24 0.275 61.0 24 – 64 – 108 0.815 0.0514

  36 0.498 55.0 36 – 36 – 96  0.820 0.047

  44 0.597 55.4 44 – 44 – 92  0.808 0.041

Which would you take :cool:

?

BTW: 100 000 simuls each. Total simul'ants time approx. 9.5 hours (with some clumsy R code).

—
Regards,

Detlew

Complete thread:

Potvin method B subtleties d_labes 2011-01-31 14:24 [Two-Stage / GS Designs]
- Potvin method B subtleties jdetlor 2011-02-01 17:17
  - Potvin method B subtleties d_labes 2011-02-02 09:15
    - Potvin method B subtleties jdetlor 2011-02-02 16:08
      - Gould d_labes 2011-02-02 16:25
        
        Gould jdetlor 2011-02-02 17:02
- Another one ... d_labes 2011-02-07 14:32
  - Oops! Helmut 2011-02-07 15:24
    - Oops! d_labes 2011-02-07 16:29
      - Oops! Helmut 2011-02-07 16:47
        
        Oops! ElMaestro 2011-02-07 17:06
        
        Oops! Helmut 2011-02-07 17:17
        
        Oops! ElMaestro 2011-02-07 18:35
        
        Simul'ants in my pantsd_labes 2011-02-08 09:07
        
        Need for speed... ElMaestro 2011-02-13 10:57
        
        Need for speed... d_labes 2011-02-15 14:06
        
        Need for speed... ElMaestro 2011-02-15 17:39
        
        Pocock alpha's d_labes 2011-02-16 09:18
        
        ElMaestro's brain ElMaestro 2011-02-16 09:32
        
        ElMaestro's brain d_labes 2011-02-16 10:05
        
        ElMaestro's brain ElMaestro 2011-02-16 12:07
        
        Numbers d_labes 2011-02-16 13:45
- Bonus counter-question ElMaestro 2011-02-07 23:44
  - Speed is the question d_labes 2011-02-08 08:36
- New paper (method D for PE 0.90) Helmut 2011-04-18 12:58
  - New paper (method D for PE 0.90) d_labes 2011-04-19 08:58
    - New paper (method D for PE 0.90) Helmut 2011-04-19 14:30
    - New paper (method D for PE 0.90) ElMaestro 2011-04-19 14:49
      - Stopping criterion # futility rule Helmut 2011-04-19 15:28