Potvin C consequences [Two-Stage / GS Designs]

posted by ElMaestro  – Denmark, 2022-06-26 11:11 (1090 d 11:58 ago) – Posting: # 23088
Views: 4,748

Hey easy now,

❝ ❝ Of course, ElMaestro is right.


While that sounds good it is only very rarely the truth. :crying:

❝ take a look at some (theoretical) situation: a Sponsor goes with Potvin C (don't ask me why), moreover, he proved that with the current CV and n1 T1E does not exceed 5%.

❝ But as you showed in the lectures and in example above, Potvin C could not ensure 5% for all combinations. Thus, during stage 1 the CV was lower and the resulted T1E was out of 5%.

❝ What would be the right (safe) way out in such situation?


I can't follow you, in particular the parts in red.
Your type I error is not depending on your estimates and thus not depending on whether you went into stage 2 or not. They are depending on the true GMR, the (true) variability, N and the underlying stats assumptions; you may have estimates of the CV and GMR and your N is known.
Note also that when we speak of type I error it is often implied that it is the maximum type I error. By definition, it is on the acceptance borders that you get an idea of the type I errors.

Pass or fail!
ElMaestro

Complete thread:

UA Flag
Activity
 Admin contact
23,424 posts in 4,927 threads, 1,674 registered users;
39 visitors (0 registered, 39 guests [including 10 identified bots]).
Forum time: 23:09 CEST (Europe/Vienna)

Complex, statistically improbable things are by their nature
more difficult to explain than
simple, statistically probable things.    Richard Dawkins

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5