Bioequivalence and Bioavailability Forum • Blind 2Stage

Blind 2Stage [Two-Stage / GS Designs]

posted by Helmut – Vienna, Austria, 2019-05-30 14:56 (2021 d 23:44 ago) – Posting: # 20306
Views: 8,242

Hi Nastia,

❝ But can you clarify me the meaning of blindness in BE trials?

You know its meaning. ;-)

Never seen ones, except for Health Canada:

2.4.2 Blinding
To avoid study bias, comparative bioavailability studies should be conducted in such a way that the subjects are not aware of which product (test or reference) is being administered.

That’s a funny idea if the products don’t look the same.

❝ […] it turns out that blinding may even worse the situation (5.01% vs 7.36%, TIE). It is connected with the unknown PE (cause for BLIND=TRUE s20s<-mses), but isn't it contrintuitive?

Yes and yes. Have a look at Figure 1 of Golkowski et al.*

❝ Can it be true for parallel design also? Suppose we want to make a blind interim analyses after first stage with N subjects and recalculate sample size on fixed GMR=0.95 if total CV would be greater than initial suggestion. Will it cause any inflation?

Possibly.

❝ How to estimate it?

Simulations… Might be tricky cause we have to think about unequal group sizes and/or variances.

BTW, do you remember Paola Coppola’s presentation at last year’s BioBridges?

[image]

Golkowski D, Friede T, Kieser M. Blinded sample size re-estimation in crossover bioequivalence trials. Pharm Stat. 2014;13(3):157–62. doi:10.1002/pst.1617.

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Complete thread:

2-stage design with interim sample size estimation d_labes 2010-10-05 15:09 [Two-Stage / GS Designs]
- 2-stage design with interim sample size estimation Jack 2010-10-25 18:20
  - Null = bioINequivalence Helmut 2010-10-25 19:16
  - 2-stage design with interim sample size estimation d_labes 2010-10-26 13:28
    - 2-stage design with interim sample size estimation Jack 2010-10-26 18:26
      - Blind or not, Indecisions or Decisions d_labes 2010-10-27 16:01
        
        Blind or not, Indecisions or Decisions Jack 2010-10-27 18:14
        
        Blind ? Ohlbe 2010-10-27 23:37
        
        Blind ? Jack 2010-10-28 10:24
        
        Blind 2Stage Astea 2019-05-30 10:37
        
        Blind 2StageHelmut 2019-05-30 12:56
        
        Blind 2Stage and an elephant Astea 2019-05-31 14:36
        
        Which elephant? Helmut 2019-06-02 20:14
        
        Blind interim in parallel design? Astea 2019-06-03 01:47
        
        Blind men d_labes 2019-06-05 12:23
        
        The Blind Leading the Blind Astea 2019-06-06 00:55