T/R ratio for estimation of sample size in BE study of NTI drugs [Power / Sample Size]
Hi Hötzi,
This strays away from the usually stringent scientific principles that this forum usually promotes, doesn't it?
We plug in the GMR that we think/predict/guess is a realistic and relevant indicator of relative product performance, possibly with a buffer to factor in worst cases. Habits, experience and gut feeling.
There is no divine aspect of NTID's, as far as I know, that makes them easier to copy than non-NTID's from a strict formulation perspective so I don't know if the default is much science based.
Although I am sure 0.975 is condoned by the guy in the Armani suit.
He would definitely also like it for non-NTID's.
Perhaps all this boils down to the use of anything "default" in a power calculation. It is extremely handy. And it is a bit dangerous. Perhaps the world would be a better place altogether if such functions did not assume defaults for CV and GMR and designs - this would force users to actually *** badum tssss *** think just a little bit about the values they plug in before deriving a power.
OK, rant over, I'll take my medicine now. Stage III syphilis...
❝ Both are fine. Note that the FDA requires tighter batch release spec’s for NTIDs. Hence, in function sampleN.NTIDFDA()
of PowerTOST
the default is 0.975 – contrary to the usual 0.95.
This strays away from the usually stringent scientific principles that this forum usually promotes, doesn't it?
We plug in the GMR that we think/predict/guess is a realistic and relevant indicator of relative product performance, possibly with a buffer to factor in worst cases. Habits, experience and gut feeling.
There is no divine aspect of NTID's, as far as I know, that makes them easier to copy than non-NTID's from a strict formulation perspective so I don't know if the default is much science based.
Although I am sure 0.975 is condoned by the guy in the Armani suit.

Perhaps all this boils down to the use of anything "default" in a power calculation. It is extremely handy. And it is a bit dangerous. Perhaps the world would be a better place altogether if such functions did not assume defaults for CV and GMR and designs - this would force users to actually *** badum tssss *** think just a little bit about the values they plug in before deriving a power.
OK, rant over, I'll take my medicine now. Stage III syphilis...
—
Pass or fail!
ElMaestro
Pass or fail!
ElMaestro
Complete thread:
- T/R ratio for estimation of sample size in BE study of NTI drugs mahmoud-teaima 2017-10-24 19:18 [Power / Sample Size]
- T/R ratio for estimation of sample size in BE study of NTI drugs Helmut 2017-10-24 23:15
- T/R ratio for estimation of sample size in BE study of NTI drugsElMaestro 2017-10-25 12:34
- T/R ratio for estimation of sample size in BE study of NTI drugs nobody 2017-10-26 14:03
- Defaults in PowerTOST d_labes 2017-10-26 14:49
- T/R ratio for estimation of sample size in BE study of NTI drugs nobody 2017-10-26 14:03
- T/R ratio for estimation of sample size in BE study of NTI drugsElMaestro 2017-10-25 12:34
- T/R ratio for estimation of sample size in BE study of NTI drugs Helmut 2017-10-24 23:15