Bioequivalence and Bioavailability Forum • A place to start?

A place to start? [Two-Stage / GS Designs]

posted by d_labes – Berlin, Germany, 2017-11-13 17:02 (2792 d 17:37 ago) – Posting: # 17974
Views: 10,401

Dear ElMaestro,

❝ can you run a series of sims where you include "20 more subjects than necessary" in stage 2 where a stage 2 is called for?

that could indeed be done within the (in)famous package Power2Stage, function power.2stage.fC() using the argument n2.min. At least partially because n2.min assures a minimum sample size for stage 2, if stage 2 is called for and the estimated sample size is smaller than n2.min.

But that's not the problem Helmut has described, at least as I understand it. Here we initiate a stage 2 from the perspective of the AUC evaluation where it is not neccessary to initiate one.

If having more than necessary number of subjects is a problem at all? My gut feeling says no.

—
Regards,

Detlew

Complete thread:

Two PK metrics: Inflation of the Type I Error Helmut 2017-11-12 11:57
- Two PK metrics: Inflation of the Type I Error? d_labes 2017-11-12 17:46
- A place to start ElMaestro 2017-11-12 21:43
  - A place to start?d_labes 2017-11-13 16:02
    - A place to start? Helmut 2017-11-13 16:51
      - Scientific gut feeling d_labes 2017-11-15 10:34
        
        Five minutes gone - power.tsd.2m() arose d_labes 2017-11-15 13:15
    - A better place to start. ElMaestro 2017-11-14 00:04
      - Nope Helmut 2017-11-14 00:21
        
        Nope nobody 2017-11-14 08:11
        I've meditated hard ElMaestro 2017-11-14 12:41