Misunderstanding? [Regulatives / Guidelines]
❝ 1. I do not understand the underlying math (just try and look into the spectral decomposition things mentioned as part of DDFM derivation; it sends my head spinning).
❝ 2. Whatever SAS does, it seems to require that we work in V through
ZGZt+R in order to estimate CI's for the fixed effects.
❝ It would be interesting to see someone who has solid understanding of matrix theory and stats to work out the equations when the between and within-variability for T cannot be separated.
Definitely not me…
❝ However, since FDA now threw the mixed model out for semi-replicate designs, …
What on earth gives you this impression? I’m talking about ABE (Stats guidance Appendix E, Progesterone guidance page 8, ANDA guidance page 29):
The following codes are an example of the determination of unscaled average BE for LAUCT with a partially replicate 3-way BE design:
CLASSES SEQ SUBJ PER TRT;
MODEL LAUCT = SEQ PER TRT/ DDFM=SATTERTH;
RANDOM TRT/TYPE=FA0(2) SUB=SUBJ G;
ESTIMATE 'T vs. R' TRT 1 -1/CL ALPHA=0.1;
ods output Estimates=unsc1;
title1 'unscaled BE 90% CI - guidance version';
If reference-scaling is acceptable (right branch), even a spreadsheet (‼) would do.
❝ … interesting may in reality just mean academically attractive but possible not too useful at this moment.
Nope. Talk to John about his data sets which didn’t converge. Given,
FA0(1)did – with a warning – but I think there is a data set posted at Certara’s forum where nothing worked. Study done, no result. THX, .
❝ But who knows - until someone does it and explores it, it is not known if there is an advantageous property hidden somewhere.
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
The quality of responses received is directly proportional to the quality of the question asked. 🚮
- Desperate reader Helmut 2021-08-27 15:51 [Regulatives / Guidelines]
- Desperate reader ElMaestro 2021-08-27 22:18
- Papers Mahmoud 2021-09-17 13:31