Q&A published 14 March 2011 [BE/BA News]

posted by ElMaestro  – Belgium?, 2011-03-16 14:20  – Posting: # 6763
Views: 26,893

Hehe,

A simple linear mixed model, which assumes identical within-subject variability (Method B), may be acceptable as long as results obtained with the two methods do not lead to different regulatory decisions. However, in borderline cases and when there are many included subjects who only provide data for a subset of the treatment periods, additional analysis using method A might be required.
At the time of protocol writing you do not know if there will be data gaps. Therefore, you cannot write which evaluation method you will ultimately be using. This means (??) that one has to apply both methods, check if the BE conclusions are the same and then, in case there are differences, discard a method which gives unbiased variance estimates.

An advantage of Method C is that it directly calculates s2wr However, sometimes the algorithm fails to converge.
No, the Al Gore Rhythm will converge if the guy doing the statistics knows what he is doing in terms of controlling the ini-values and other optimizer settings (flat multidimensional likelihood surfaces are hypothetical).

Complete thread:

Activity
 Mix view
Bioequivalence and Bioavailability Forum |  Admin contact
19,810 posts in 4,198 threads, 1,360 registered users;
online 8 (1 registered, 7 guests [including 5 identified bots]).
Forum time (Europe/Vienna): 07:26 CEST

A big computer, a complex algorithm and a long time
does not equal science.    Robert Gentleman

The BIOEQUIVALENCE / BIOAVAILABILITY FORUM is hosted by
BEBAC Ing. Helmut Schütz
HTML5