PowerTOST sample size EMA full replicate [🇷 for BE/BA]

posted by Astea – Russia, 2016-03-24 20:34 (3385 d 04:19 ago) – Posting: # 16135
Views: 10,604

Dear all!
I've noted that sample size, estimated with the help of PowerTOST's scABEL, depends on the difference between CV_T and CV_R.
Suppose we have a HVD with unknown CV (or CV is known in literature but it ranges widely through the studies). There could be a situation when CV_T and CV_R do not coincides. For example, CV_R=0.3 and CV_T=0.4. Then basing on the sampleN.scABEL for theta0=0.9 we need 48 subjects. But if we plan replicate study on the basis of CV=0.3 we get only 34 subjects. Moreover planing replicate study without scaling (sampleN.TOST) we get only 40 subjects. Here I post the graph for illustration purposes (scABEL2 denotes sampleN.scABEL(CV=c(CV_T, 0.3), theta0=0.9, design="2x2x4"))
Do I undestand correctly? If it so then there are always exist a miserable possibility that calculated by scABEL with CV_T=CV_R sample size would be insufficient?

[image]


"Being in minority, even a minority of one, did not make you mad"

Complete thread:

UA Flag
Activity
 Admin contact
23,425 posts in 4,928 threads, 1,682 registered users;
32 visitors (0 registered, 32 guests [including 12 identified bots]).
Forum time: 01:54 CEST (Europe/Vienna)

I think it is much more interesting to live with uncertainty
than to live with answers that might be wrong.    Richard Feynman

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5