Bear to bear interval with 90% confidence [🇷 for BE/BA]

posted by ElMaestro  – Denmark, 2009-04-01 23:28 (6281 d 13:17 ago) – Posting: # 3448
Views: 15,724

(edited on 2009-04-02 07:56)

Hi again,

❝ ❝ And this is exactly what we need for the BE evaluation,

❝ ❝ because log(LSMean(T)/LSMean(R))=log(LSMean(T)-log(LSMean(R))[...]


❝ Interesting points. Do you mean for unbalanced data or for all kinds

❝ here? I don't know this before.


Yes, this is actually the easy part.
If you use something like this:

TotallyFantasticFit=lm(lnAUC~Subj+Seq+Per+Trt)

Then you can get the difference in LSMeans via:
summary(TotallyFantasticFit)

Note that the sign of the treatment effect will be depending on the way the data have been garbled initially: It will be equal to either (LSMean(T)-LSMean(R)) or to (LSMean(R)-LSMean(T)) so be aware of the sign.

The alternative way to do it is to simply calculate LSMeans by averaging over the sequences, see Chow & Liu's book.

It is solely a matter of taste.
Your end result (T/R ratio) will be the same regardless. And it will work for balanced as well as unbalanced datasets.

EM.

Edit 02.04.09: Error in my explanation of LSMean calculation.

Complete thread:

UA Flag
Activity
 Admin contact
23,653 posts in 4,991 threads, 1,570 registered users;
113 visitors (0 registered, 113 guests [including 36 identified bots]).
Forum time: 12:46 CEST (Europe/Vienna)

To propose that poor design can be corrected by subtle analysis techniques
is contrary to good scientific thinking.    Stuart J. Pocock

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