Bioequivalence and Bioavailability Forum • “Forced BE” 101

“Forced BE” 101 [Power / Sample Size]

posted by Helmut – Vienna, Austria, 2017-12-27 11:23 – Posting: # 18097
Views: 19,906

» what about regulatory queries on "unintentional forced Bioequivalence"

What do you mean by unintentional?
Again: Stop estimating post hoc power! Either the study demonstrated BE or not.*
Going back to my example (study planned for 90% power): The chance to obtain a post hoc power of ≥95% is ~35%. Now what?
It only means that

the CV was lower and/or
the GMR closer to 1 and/or
you had less dropouts than assumed.

However, the patient’s risk (α = probability of the Type I Error) is independent from the producer’s risk (β = probability of the Type II Error). The latter might be of concern for the IEC in study planning (see Yura’s example) whereas only the former is of regulatory concern – and not affected by power.

I still think that you calculations are wrong. Therefore, you are facing high values more often. Would you mind giving us the data ElMaestro and I asked for?

If the CV, GMR, number of dropouts are “worse” than assumed, there is still a chance to show BE – though with less than the desired power. If you succeeded, fine.
If post hoc power is correctly (!) estimated, it will be always low for a failed study.

—
Cheers,
Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. ☼
Science Quotes

Complete thread:

Power is getting high kms.srinivas 2017-12-26 07:39 [Power / Sample Size]
- Power is getting high? d_labes 2017-12-26 12:08
- Stop estimating post hoc power! Helmut 2017-12-26 12:22
  - Stop estimating post hoc power! kms.srinivas 2017-12-26 13:00
    - Stop estimating post hoc power! ElMaestro 2017-12-26 14:11
    - Simulations Helmut 2017-12-26 15:51
      - Simulations BE-proff 2017-12-27 06:53
        
        Simulations ElMaestro 2017-12-27 07:25
        Simulations Yura 2017-12-27 08:23
        
        Simulations kms.srinivas 2017-12-27 09:11
        
        Simulations Yura 2017-12-27 10:07
        
        α and 1–β Helmut 2017-12-27 12:57
        
        α and 1–β Yura 2017-12-27 13:33
        
        α and 1–β Helmut 2017-12-27 14:31
        
        α and 1–β Yura 2017-12-28 06:50
        
        Educate the IEC and regulators Helmut 2017-12-28 11:30
        
        “Forced BE” 101 Helmut 2017-12-27 12:23
        
        “Forced BE” 101 kms.srinivas 2017-12-27 12:41
        
        Would you be so kind answering our questions? Helmut 2017-12-27 13:02
        
        Would you be so kind answering our questions? kms.srinivas 2017-12-28 05:53
        
        Yes, but why? Helmut 2017-12-28 11:47
        
        Yes, but why? DavidManteigas 2017-12-28 16:59
        
        Optimists and pessimists Helmut 2017-12-28 17:33
        
        "normal" GMR setting d_labes 2017-12-28 18:57
        
        Example for discussion mittyri 2017-12-28 22:06
        
        Example for discussion Helmut 2017-12-28 22:33
        
        I prefer to play it safe Helmut 2017-12-28 22:10
        
        Full ACK d_labes 2017-12-28 17:41
        About GMR 1.10 kms.srinivas 2017-12-29 13:20
        
        Better 0.95 or 0.90 Helmut 2017-12-29 16:18
        
        Yes, but why? Yura 2017-12-29 13:46
        Buffon's needle Astea 2018-01-20 23:55
        
        Buffon's needle Oleg777 2018-10-09 22:48
        
        0.95 or 1.05 Helmut 2018-10-10 13:41
        
        Buffon's needle Helmut 2018-10-10 12:46
        
        Buffon's needle Astea 2018-10-11 23:14
        
        School maths Helmut 2018-10-12 01:10
        
        School russian Astea 2018-10-12 12:41
        Offtop: Umschrift der westlichen Eigennamen auf Russisch mittyri 2018-10-12 23:25
        
        EEU? mittyri 2017-12-28 21:52
        
        EEU? Yura 2017-12-29 13:41
        
        EEU - pharmacokinetic equation??? mittyri 2017-12-29 14:11
        
        EEU? Beholder 2018-01-16 15:10
        
        Simulations xtianbadillo 2018-01-18 22:22
- Numbers don't lie ElMaestro 2017-12-28 20:13