FDA loves replicate bears? [🇷 for BE/BA]
Dear Yung-jin,
This was because I could not identify the syntax to implement such things (FA0(2) or CSH) within lme() and I had the guess that the lme() output
corresponds eventually to SAS UN parameterization. BTW could not find any hint up to now what this really means: General positive-definite, Log-Cholesky parametrization. Questions for that are always answered: Buy the book of Pinheiro/Bates "Mixed-Effects Models in S and S-PLUS", Springer (2000), there it is described. But recent I am a little short in money. We have a financial crisis .
Sure! As long as ...
But the FDA statistical guidance explicitly states the model with different inter/intra-subject variabilities (Proc MIXED code in appendix G, I think) in evaluating ABE in replicate studies.
And this is not the model implemented at present in bear for evaluation of replicate studies.
I myself are convinced that the assumptions of no subject-by-treatment interaction and equal within subject variabilities are reasonable if we talk about ABE. Although with these assumptions an advantage of replicate designs vanishes, namely that we are able to study different variabilities.
But unfortunately statistically correct or reasonable is in regulators view not always correct or reasonable.
Not so astonishing because statisticians are them selfs of such different opinions if I think about Type III SumOfSqares or now the question of denominator degrees of freedom.
❝ I don't know why you used TYPE=UN in your SAS code. [...]
This was because I could not identify the syntax to implement such things (FA0(2) or CSH) within lme() and I had the guess that the lme() output
"Random effects:
Formula: ~tmt - 1 | subject
Structure: General positive-definite, Log-Cholesky parametrization"
corresponds eventually to SAS UN parameterization. BTW could not find any hint up to now what this really means: General positive-definite, Log-Cholesky parametrization. Questions for that are always answered: Buy the book of Pinheiro/Bates "Mixed-Effects Models in S and S-PLUS", Springer (2000), there it is described. But recent I am a little short in money. We have a financial crisis .
❝ [...] As long as bear complies with the FDA Guidance (2001) and is statistically correct, it should be acceptable, I guess.
Sure! As long as ...
But the FDA statistical guidance explicitly states the model with different inter/intra-subject variabilities (Proc MIXED code in appendix G, I think) in evaluating ABE in replicate studies.
And this is not the model implemented at present in bear for evaluation of replicate studies.
I myself are convinced that the assumptions of no subject-by-treatment interaction and equal within subject variabilities are reasonable if we talk about ABE. Although with these assumptions an advantage of replicate designs vanishes, namely that we are able to study different variabilities.
But unfortunately statistically correct or reasonable is in regulators view not always correct or reasonable.
Not so astonishing because statisticians are them selfs of such different opinions if I think about Type III SumOfSqares or now the question of denominator degrees of freedom.
—
Regards,
Detlew
Regards,
Detlew
Complete thread:
- Freedom for replicate bears d_labes 2009-04-17 12:06 [🇷 for BE/BA]
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- Contain does not contain d_labes 2009-04-17 15:07
- Freedom for replicate bears ElMaestro 2009-04-18 03:45
- Freedom incompatible with baseball bats d_labes 2009-04-20 08:42
- Freedom for replicate bears yjlee168 2009-04-19 21:38
- Freedom to some degree d_labes 2009-04-20 08:30
- Freedom to some degree yjlee168 2009-04-21 14:03
- FDA loves replicate bears?d_labes 2009-04-21 16:11
- Cholesky factor ?! Helmut 2009-04-22 00:46
- Cholesky factor ?! d_labes 2009-04-22 11:20
- FDA loves replicate bears? yjlee168 2009-04-23 08:08
- FDA loves SAS code? d_labes 2009-04-23 09:48
- FDA loves SAS code? definitely. yjlee168 2009-04-23 10:46
- SAS? or R? or what? d_labes 2009-04-23 15:07
- SAS? or R? or what? Helmut 2009-04-23 15:25
- SAS? or R? or what? d_labes 2009-04-23 16:06
- SAS? or R? or what? Helmut 2009-04-23 16:30
- SAS? or R? or what? d_labes 2009-04-23 16:06
- SAS? YES; R? why not? as long as they are useful... yjlee168 2009-04-23 19:56
- New Forum-Category 'bear'? Helmut 2009-04-23 20:03
- New Forum-Category 'bear'? yjlee168 2009-04-23 20:19
- New Forum-Category 'R for BE/BA' Helmut 2009-04-23 20:37
- New Forum-Category 'R for BE/BA' yjlee168 2009-04-24 09:19
- New Forum-Category 'R for BE/BA' Helmut 2009-04-23 20:37
- New Forum-Category 'bear'? yjlee168 2009-04-23 20:19
- Replicated again d_labes 2009-04-24 08:27
- Replicated again yjlee168 2009-04-24 09:26
- New Forum-Category 'bear'? Helmut 2009-04-23 20:03
- SAS? or R? or what? Helmut 2009-04-23 15:25
- SAS? or R? or what? d_labes 2009-04-23 15:07
- FDA loves SAS code? definitely. yjlee168 2009-04-23 10:46
- FDA loves SAS code? d_labes 2009-04-23 09:48
- Cholesky factor ?! Helmut 2009-04-22 00:46
- FDA loves replicate bears?d_labes 2009-04-21 16:11
- Freedom to some degree yjlee168 2009-04-21 14:03
- Freedom to some degree d_labes 2009-04-20 08:30
- getting decimals ElMaestro 2010-06-03 05:21
- getting decimals yjlee168 2010-06-03 08:37
- getting decimals ElMaestro 2010-06-04 01:59
- getting decimals yjlee168 2010-06-03 08:37
- Freedom for replicate bears ElMaestro 2011-01-27 21:50
- lmer vs. lme d_labes 2011-01-28 09:02
- lmer vs. lme ElMaestro 2011-01-28 09:42
- lmer vs. lme d_labes 2011-01-28 11:37
- V ElMaestro 2011-01-28 12:14
- V corrected d_labes 2011-01-28 14:12
- V corrected ElMaestro 2011-01-28 15:20
- Peculiar partial replicate d_labes 2011-01-28 16:10
- V corrected ElMaestro 2011-01-28 15:20
- V corrected d_labes 2011-01-28 14:12
- V ElMaestro 2011-01-28 12:14
- lmer vs. lme d_labes 2011-01-28 11:37
- lmer vs. lme ElMaestro 2011-01-28 09:42
- lmer vs. lme d_labes 2011-01-28 09:02
- Freedom for replicate bears ElMaestro 2009-04-17 14:50