Bioequivalence and Bioavailability Forum

Oops! [Two-Stage / GS Designs]

posted by Helmut  – Vienna, Austria, 2011-02-07 17:47 (5249 d 00:58 ago) – Posting: # 6570
Views: 26,778

Dear D. Labes!

❝ According to their formula given in paragraph 2.3 they use the approximation via central shifted Student's t-distribution, …

❝ Check it via the undocumented and hidden function …

Ah, funny.

❝ But what you discuss was not my point, I think.

I know - and knew. I was carried away be reading the paper again and to be honest for the first time I recalculated the examples.

❝ Or was your first sentence already the answer?

Come on!

❝ I need to know the power of Potvin B/C if I assume 'true' GMR=1.08, 'true' CV = 0.3 for instance.

Sure. I’m a little bit confused right now, because it seems that I misunderstood the decision procedure. Until you came up with your nice question I thought that the power calculation is done on the actual PE of stage 1 (1.08, not 0.95) and only the sample size calculation is done with 0.95 (no adaption for effect size). From the examples the former is not true – both are done with 0.95. Now I'm stuck. Potvin’s simulations were done with 0.95; is it that simple to use e.g. 0.90 instead?

—
Dif-tor heh smusma 🖖🏼 Довге життя Україна! 
Helmut Schütz


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Science Quotes

Complete thread:

• Potvin method B subtleties d_labes 2011-01-31 14:24 
  • 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 pants d_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