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RegisterThird opinion [RSABE / ABEL]
Hi John,
Here I am! But don't know if I can help anyway. The whole story "Use Proc MIXED code for Partial replicate design" is mysterious to me.
No.
As Helmut already pointed out: an ambiguous attempt of the REML algo to obtain the within-subject variance of the Test formulation. But IMHO the model is over-specified (s2D + s2wT not separable, see below) and therefore there is no guarantee that the value obtained is reasonable.
Correct. Unambiguously identifiable.
Not clear to me what a 90% geometric CI is
.
The difference µT-µR has as standard error associated with it for the partial replicate design
where s2D is the variance of the subject-by-formulation interaction, ni are the number of subjects in the sequence groups, seq is the number of sequences.
s2D can be obtained from the G-matrix according to
(see for more details this post).
Since the model seems over-specified try to use a simple model, f.i. neglect s2D which in turn results in a CS variance-covariance structure for the random part. Sometimes this helps.
See also this thread for another even simpler model specification.
BTW: @Helmut, asking the FDA seems a very good idea!
❝ Detlew, need help! 
Here I am! But don't know if I can help anyway. The whole story "Use Proc MIXED code for Partial replicate design" is mysterious to me.
❝ Here is the covariance output from SAS on ln AUCt
❝
❝ Covariance Parameter Estimates
❝ Cov Parm Subject Group Estimate
❝ FA(1,1) subject 0.4427
❝ FA(2,1) subject 0.4236
❝ FA(2,2) subject 0.2481
❝ Residual subject formulation Ref 0.05301
❝ Residual subject formulation Test 0.02648
❝
❝ Question, what does the residual "formulation Test" represent? Is it the residual attributed to both test and ref
No.
As Helmut already pointed out: an ambiguous attempt of the REML algo to obtain the within-subject variance of the Test formulation. But IMHO the model is over-specified (s2D + s2wT not separable, see below) and therefore there is no guarantee that the value obtained is reasonable.
❝ while residual "formulation ref" is attributed to the ref (since it was given 2x)?
Correct. Unambiguously identifiable.
❝ which one would one use to compute the 90% geometric CI then?
Not clear to me what a 90% geometric CI is
.The difference µT-µR has as standard error associated with it for the partial replicate design
sd = sqrt((s2D + s2wT + s2wR/2)*sum(1/ni)/seq^2)where s2D is the variance of the subject-by-formulation interaction, ni are the number of subjects in the sequence groups, seq is the number of sequences.
s2D can be obtained from the G-matrix according to
s2D = g11+g22-2*g12(see for more details this post).
Since the model seems over-specified try to use a simple model, f.i. neglect s2D which in turn results in a CS variance-covariance structure for the random part. Sometimes this helps.
See also this thread for another even simpler model specification.
BTW: @Helmut, asking the FDA seems a very good idea!
—
Regards,
Detlew
Regards,
Detlew
Complete thread:
- FDA's HVD SAS Code from Progesterone Guidance jag009 2013-04-22 16:39
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Proc MIXED vs. Proc GLM Helmut 2013-04-22 17:47
- Proc MIXED vs. Proc GLM jag009 2013-04-22 20:33
- SAS vs. PHX Helmut 2013-04-22 22:10
- SAS vs. PHX Shuanghe 2013-04-23 11:45
- SAS vs. SAS d_labes 2013-04-23 16:50
- SAS vs. SAS vs. Phoenix Helmut 2019-11-12 13:01
- SAS vs. SAS d_labes 2013-04-23 16:50
- SAS vs. PHX jag009 2013-04-23 15:56
- SAS Warning (Note) on Proc Mixed jag009 2013-04-23 17:07
- Nut Job.. jag009 2013-04-30 21:09
- Second opinion (PHX 6.3) Helmut 2013-05-01 16:21
- Second opinion (PHX 6.3) jag009 2013-05-01 17:16
- Second opinion (PHX 6.3) ElMaestro 2013-05-01 18:48
- In praise of a full replicate Helmut 2013-05-01 19:16
- Third opiniond_labes 2013-05-02 12:00
- Compound Symmetry Helmut 2013-05-02 14:41
- Compound Symmetry - SASian (1) d_labes 2013-05-02 16:26
- Variance=0 Helmut 2013-05-03 16:07
- Compound Symmetry - SASian (1) d_labes 2013-05-02 16:26
- Compound Symmetry Helmut 2013-05-02 14:41
- Second opinion (PHX 6.3) jag009 2013-05-01 17:16
- Second opinion (PHX 6.3) Helmut 2013-05-01 16:21
- Nut Job.. jag009 2013-04-30 21:09
- SAS Warning (Note) on Proc Mixed jag009 2013-04-23 17:07
- SAS vs. PHX Shuanghe 2013-04-23 11:45
- SAS vs. PHX Helmut 2013-04-22 22:10
- Proc MIXED vs. Proc GLM jag009 2013-04-22 20:33
- Proc MIXED vs. Proc GLM Helmut 2013-04-22 17:47
Ing. Helmut Schütz