Bioequivalence and Bioavailability Forum • Lower bound for power of two combined TOST?

Lower bound for power of two combined TOST? [Power / Sample Size]

posted by d_labes – Berlin, Germany, 2018-07-25 16:46 (2372 d 00:23 ago) – Posting: # 19100
Views: 5,685

Dear ElMaestro,

❝ ❝

Power >= PAUC + PCmax - (2 - 1)

where PAUC is the estimate of power for AUC and PCmax is the estimate of power for Cmax.

❝ Surely that's either wrong or an approximation that has some validity within a set of strict conditions. I have not read that work or reference 918, but it looks outright wrong.

Here we are two.
You may read under the link

https://books.google.de/books?id=e3byCOxj8FoC&pg=PA45

some more sparse details. Unfortunately the Appendix D with a proof of that formula is not available in Gooooogle books.

❝ With that equation power could become negative, go figure.

One nitpicking: The lower bound of power could become negative if both powers are <0.5, values no one would use in estimating sample sizes. If such a bound is reasonable is of course highly questionable.

—
Regards,

Detlew

Complete thread:

Lower bound for power of two combined TOST? d_labes 2018-07-25 10:40 [Power / Sample Size]
- Lower bound for power of two combined TOST? ElMaestro 2018-07-25 12:07
  - Lower bound for power of two combined TOST?d_labes 2018-07-25 14:46
    - Appendix D mittyri 2018-07-26 00:07
      - Appendix D d_labes 2018-07-26 13:41
- Use of lower bound for power of two combined TOST d_labes 2018-07-26 14:29
  - Use of lower bound for power of two combined TOST Ben 2018-08-06 18:11
    - Use of lower bound for power of two combined TOST d_labes 2018-08-07 11:50