Validated frameworks; observed GMR not relevant [Two-Stage / GS Designs]

posted by Silva – Portugal, 2017-03-09 01:26  – Posting: # 17143
Views: 9,718

Hi Helmut

Trying to learn technical issues of TSD.

In the example you gave:

library(Power2Stage)
 power.2stage(CV=0.2, n1=12, alpha=c(0.0294, 0.0294), theta0=1.25,
              targetpower=0.8, pmethod="shifted", nsims=1e6)$pBE
 # [1] 0.046352
# n1 within validated range: TIE <0.05.

why the use of theta0 as 1.25 and not as GMR value? I understand the use of GMR of 0.95 for Potvin B method (as it was validated with this assumption), but don´t understant the meaning of theta0.

According to Power2Stage manual, theta 0 corresponds to the True ratio of T/R for simulating. (Defaults to the GMR argument if missing).

What is the meaning of "True ratio of T/R for simulating" and what is the difference for GMR?

Complete thread:

Activity
 Admin contact
20,463 posts in 4,297 threads, 1,415 registered users;
online 6 (1 registered, 5 guests [including 6 identified bots]).
Forum time (Europe/Vienna): 01:52 CEST

Half of the modern drugs could well be thrown out of the window,
except that the birds might eat them.    Martin H. Fischer

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