Bioequivalence and Bioavailability Forum • Plausible to me too

Plausible to me too [Power / Sample Size]

posted by ElMaestro – Denmark, 2017-02-06 23:30 (2627 d 07:03 ago) – Posting: # 17026
Views: 25,745

Let P0= P(GMR<U)-P(GMR<L) regardless of what U and L are, as long as they are meaningful (U>L, and not negative). This quantitiy is easuily accessible via Power.TOST. If L and U are BE acceptance limits then P0 is power in a BE trial.

We can rewrite that as
P0=P(GMR in [L,U]), regardless of what U and L are, as long as they are meaningful (U>L, and not negative)

If we define L=0.8 and U=1.25 and GMR is within these limits, then we can say that P0 falls in (is composed of) three categories:
1. Those that have GMR in [L, 1.0]
2. Those that have GMR in [1.0, U]
3. Anything that isn’t 1 or 2.

Because “3” is anything else than 1 or 2, P1+P2+P3=P0.
and because 1 and 2 are mutually exclusive (can’t fall in both categories), except the zero-prob of GMR exactly 1.0. P1 and P2 are meaningfully additive, and P1+P2 will thus be the probability of having a passing study in which 1.0 isn’t in the acceptance range when L=0.8 and U=1.25. The probability we are looking for is P3, because this is a study fulfiling P(GMR in [L,U]) but not those that have GMR in [L, 1.0] and not those that have GMR in [1.0, U], therefore P3=P0-P1-P2, so we just plug in the relevant limits in Power.TOST and Bob’s your uncle.

—
Pass or fail!
ElMaestro

Complete thread:

Denmark Curiosa (1 in 90% CI in 0.8-1.25) zizou 2017-02-05 02:03 [Power / Sample Size]
- Kudos! Helmut 2017-02-05 19:16
  - Kudos! ElMaestro 2017-02-05 21:15
    - Joking! Helmut 2017-02-06 13:27
      - Thanks, and DKMA ElMaestro 2017-02-06 13:46
        
        Power with a Danish twist Helmut 2017-02-07 15:23
        
        Danish ultra-conservatism d_labes 2017-02-08 10:57
        
        Danish ultra-conservatism Helmut 2017-02-08 11:47
    - Kudos to ElMaestro! d_labes 2017-02-06 15:06
      - Plausible Helmut 2017-02-06 17:16
        
        Plausible to me too d_labes 2017-02-06 20:25
        
        Plausible to me tooElMaestro 2017-02-06 22:30
        Plausible to me too zizou 2017-02-06 22:42
        
        THX d_labes 2017-02-07 10:01
- 3D Helmut 2017-02-06 13:47
- Denmark Curiosa (1 in 90% CI in 0.8-1.25) d_labes 2017-02-06 14:54
  - Denmark Curiosa (1 in 90% CI in 0.8-1.25) zizou 2017-02-08 21:03
    - Alternative CI for BE decision d_labes 2017-02-09 11:18
      - Alternative CI for BE decision ElMaestro 2017-02-09 11:36
        
        Alternative CI for BE decision d_labes 2017-02-09 11:48
        
        How decidedly odd ElMaestro 2017-02-09 13:28
        
        How decidedly odd zizou 2017-02-09 14:42
        
        Alternative CI for BE decision Helmut 2017-02-09 13:41
        
        No alternative d_labes 2017-02-09 20:37
        
        No alternative ElMaestro 2017-02-10 13:51
        
        No alternative? mittyri 2017-02-10 15:28
        
        Dinamarka? d_labes 2017-02-10 20:10
        
        OT: Czech beer d_labes 2017-02-10 19:57
- Denmark Curiosa (1 in 90% CI in 0.8-1.25): Gone Helmut 2019-11-08 12:47