Bioequivalence and Bioavailability Forum • Phoenix/WinNonlin

Phoenix/WinNonlin - power [Two-Stage / GS Designs]

posted by Helmut – Vienna, Austria, 2013-10-09 20:19 (4275 d 05:19 ago) – Posting: # 11636
Views: 20,952

Hi Detlew & Karthik,

❝ […] the power calculated in WinNonlin is the power for a test of difference and not the power for a test of equivalence which in Bioequivalence studies has to be used.

❝

❝ At least in 2011 (date of the thread) this was so. As Helmut's numbers show it seems unchanged up to now.

Yep. Wrong in all versions up to the current release (6.3.0.395). Pharsight is considering a calculation for BE based on the noncentral t in v6.4 (scheduled for the 1^st half of 2014). In the last internal release I saw (v6.4.0.334 of 29 May) there was already a function Power_TOST based on the shifted central t implemented. From an example on the Extranet (CV 0.233927817734416, T/R 1.04658784494175, n 20):

power.TOST(…, method='exact') 0.72740071 power.TOST(…, method='noncentral') 0.72740028 power.TOST(…, method='shifted') 0.71966084 Phoenix/WinNonlin 6.4.0.334 Power_TOST 0.71966088

Still an approximation of an approximation, but not completely off. There is hope. ;-)

Edit 2014-01-10: Pre-release V1.4 (Core Version 21Nov2013)

Phoenix/WinNonlin 6.4.0.511 Power_TOST 0.72740029 Yeah!

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Complete thread:

Potvin’s 2-stage adaptive design GSD 2012-08-17 20:56
- Potvin’s 2-stage adaptive design + RSABE/ABEL Helmut 2012-08-18 00:39
  - Potvin’s 2-stage adaptive design + RSABE/ABEL GSD 2012-08-31 16:30
    - Tough job Helmut 2012-08-31 18:37
      - Tough job GSD 2012-08-31 19:23
        
        C/D for EMA? Good luck! Helmut 2012-09-01 15:09
      - Surprise? d_labes 2012-09-05 12:57
        
        Got it. Ages for sims to complete Helmut 2012-09-05 13:35
        
        Life belt d_labes 2012-09-05 14:51
        
        Life belt Helmut 2012-09-05 15:20
  - Power for Two stage Design K2K 2013-10-07 14:43
    - Power for Two stage Design Helmut 2013-10-07 14:59
      - Power for Two stage Design K2K 2013-10-08 14:35
        
        “Interim power” Helmut 2013-10-08 14:58
        
        “Interim power” K2K 2013-10-09 12:39
        
        Validation of PowerTOST Helmut 2013-10-09 14:10
        Phoenix/WinNonlin - power d_labes 2013-10-09 16:11
        
        Phoenix/WinNonlin - powerHelmut 2013-10-09 18:19
        
        power K2K 2013-10-10 08:36