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RegisterT/R ratio for estimation of sample size in BE study of NTI drugs [Power / Sample Size]
posted by Helmut 
– Vienna, Austria, 2017-10-25 01:15 (2369 d 02:04 ago) – Posting: # 17917
Views: 7,159
Salam Mahmoud,
Both are fine. Note that the FDA requires tighter batch release spec’s for NTIDs. Hence, in function
❝ Pease, advise me about what is the best T/R ratio to be used for estimating sample size for a BE study of NTI drugs? knowing that the GL to be followed set the 90% CI acceptance range to (90-111.11) for Cmax if a "2x2x2" design be followed.
❝ I'm confused to use T/R ratio of 0.95 or 0.975?!
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.library(PowerTOST)
sampleN.NTIDFDA(CV=0.0945)
+++++++++++ FDA method for NTID's +++++++++++
Sample size estimation
---------------------------------------------
Study design: 2x2x4
log-transformed data (multiplicative model)
1e+05 studies for each step simulated.
alpha = 0.05, target power = 0.8
CVw(T) = 0.0945, CVw(R) = 0.0945
True ratio = 0.975
ABE limits = 0.8 ... 1.25
Implied scABEL = 0.9054 ... 1.1044
Regulatory settings: FDA
- Regulatory const. = 1.053605
- 'CVcap' = 0.2142
Sample size search
n power
16 0.777210
18 0.831050—
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Helmut Schütz
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
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]
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- T/R ratio for estimation of sample size in BE study of NTI drugsHelmut 2017-10-24 23:15
- T/R ratio for estimation of sample size in BE study of NTI drugs ElMaestro 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 drugs ElMaestro 2017-10-25 12:34
- T/R ratio for estimation of sample size in BE study of NTI drugsHelmut 2017-10-24 23:15
Ing. Helmut Schütz