Bioequivalence and Bioavailability Forum

Decision scheme without (?) power check [Two-Stage / GS Designs]

posted by d_labes  – Berlin, Germany, 2011-10-26 15:00 (5350 d 12:28 ago) – Posting: # 7545
Views: 22,046

Dear Ol Captain,

What about this one (variant of Potvin B):
  Evaluate BE at stage 1
  at alpha=alpha1=0.005
      ↓              ↓
if BE met:       if BE not met:
stop: success    Calculate sample size nest
                 with GMR=0.95, alpha2=0.048
                 and variance (CV) from stage 1
                     ↓                     ↓
                 if nest≤n1            if nest>n1
                     ↓                     ↓
             Evaluate BE at stage1     Continue to stage 2 with
             with alpha2=0.048          n2=nest - n1 additional subjects
                     ↓                     ↓
             Stop: sucess or fail      Evaluate after stage 2 with alpha2=0.048
                                       using data from both stages
                                               ↓
                                       success or fail

To be honest, this scheme of course is not without a power check . The power check step is only hidden in testing n_est ≤ or > n₁.

Complete thread:

• 2-stage design - power evaluation d_labes 2011-10-12 11:10 [Two-Stage / GS Designs] 
  • No opinions out there? d_labes 2011-10-26 09:14
    • Opinion yes, answer no ElMaestro 2011-10-26 11:15
      • Decision scheme without (?) power checkd_labes 2011-10-26 13:00
        • Decision scheme without (?) power check ElMaestro 2011-10-26 13:20
          • Decision scheme 'without' power check d_labes 2011-10-26 14:51
            • Decision scheme 'without' power check ElMaestro 2011-10-26 15:24
              • Numerical example d_labes 2011-10-26 16:28
                • Numerical example ElMaestro 2011-10-26 16:49
                  • Potvin C with unsymmetrical alphas d_labes 2011-10-27 14:54
                    • Potvin B, C, or D? Helmut 2011-10-27 22:52
                    • Two-stage (classical Pocock) and the FDA Helmut 2011-10-31 02:36
  • Weirdo paper ElMaestro 2011-11-30 18:04
    • Weirdo paper Helmut 2011-11-30 23:45
      • Weirdo paper ElMaestro 2011-12-01 07:16