Bioequivalence and Bioavailability Forum • ♩ ♪♫♬`·.¸¸.·´`·.¸¸.

♩ ♪♫♬`·.¸¸.·´`·.¸¸. [Two-Stage / GS Designs]

posted by Helmut – Vienna, Austria, 2015-06-02 03:52 (3582 d 12:30 ago) – Posting: # 14890
Views: 19,914

¡ Hola el Jeffe !

❝ We are trying to build confidence in the point estimate, this is the whole point of the (any) BE study. At a time when we have very little confidence in it we will not be rewarded from trying to make use of it. That is in a nutshell why the two-stage approaches do not work when we try to use the PE from stage 1.

Yep.

❝ I think we need it published, …

Sooner or later. Mainly (solely?) so satisfy our egos. It is not particularly new that adjusting for the observed GMR sucks in terms of power.^1,2 Nobody seemingly reads this stuff… Why should anybody read ours?

❝ … or some other way to get the message across.

Ahem. How / where?

❝ Telling companies that it doesn't work, well... doesn't work.

Yes. See the end of this post. Same company, two countries.
1^st training:

»Our statisticians [plural!] told us that there is no problem.« – »??‽!«
These “experts” did not participate. BE too primitive topic for them? Anything below the Kullback-Leibler divergence seems to be of no interest to them.*

2^nd training:

Statistician present. »I have been told that you routinely use Haybittle-Peto? Did you try to assess the type I error?« – »We always use SAS, which is validated.« – »??‽!«

❝ "Mr. Birdsong is not helping the project forward." vs "Mr. Birdsong is offering an opportunity to avoid a sad and brainless waste of money." The interpretation is commonly the former, rarely the latter :-D

Good story, ♩ ♪♫♬! You speak from my ♥.

Jennison C, Turnbull BW. Mid-course sample size modification in clinical trials based on the observed treatment effect. Stat Med. 2003;22(6):971–93. doi 10.1002/sim.1457
Tsiatis AA, Mehta C. On the inefficiency of the adaptive design for monitoring clinical trials. Biometrika. 2003;90(2):367–78. doi 10.1093/biomet/90.2.367

When EMA’s BE-GL was drafted I tried to interest The International Biometric Society in the topic. Not a single response.

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

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes

Complete thread:

Does unequal alpha distribution make sense? Dr_Dan 2015-05-19 08:29 [Two-Stage / GS Designs]
- Maybe; but watch the TIE! Helmut 2015-05-28 15:04
  - Advantages d_labes 2015-06-05 09:35
    - Advantages ElMaestro 2015-06-05 10:07
      - Advantages – performance measure d_labes 2015-06-05 11:21
        
        Advantages – performance measure Helmut 2015-06-05 13:29
        
        Advantages – performance measure d_labes 2015-06-05 21:27
        
        Advantages – performance measure Helmut 2015-06-05 23:29
        
        Histogram wonder d_labes 2015-06-06 12:58
        
        Histogram charlatanry Helmut 2015-06-09 13:43
        
        Histogram beauty d_labes 2015-06-09 14:55
        
        Histogram beast Helmut 2015-06-09 15:24
- Does unequal alpha distribution make sense? Dr_Dan 2015-05-29 08:33
  - Does unequal alpha distribution make sense? ElMaestro 2015-05-29 09:31
    - Does unequal alpha distribution make sense? nobody 2015-05-29 12:56
      - Old beliefs die hard Helmut 2015-05-29 13:27
        
        Old beliefs die hard nobody 2015-05-29 13:41
        
        Old beliefs die hard Helmut 2015-05-29 18:08
        
        Old beliefs die hard ElMaestro 2015-05-29 18:57
        
        Old beliefs die hard nobody 2015-05-29 20:06
        ♩ ♪♫♬`·.¸¸.·´`·.¸¸.Helmut 2015-06-02 01:52
        
        TSD only an option in exceptional cases Dr_Dan 2015-06-02 08:00
        
        TSD only an option in exceptional cases nobody 2015-06-02 09:23
        
        OT Helmut 2015-06-02 12:07
        
        OT nobody 2015-06-02 12:41
- Banana splits Helmut 2015-06-02 00:48