Bioequivalence and Bioavailability Forum • Compound Symmetry

Compound Symmetry - SASian (1) [RSABE / ABEL]

posted by d_labes – Berlin, Germany, 2013-05-02 18:26 (4432 d 22:31 ago) – Posting: # 10529
Views: 25,788

Dear Helmut,

❝ What do you SASians get?

Aye, aye Sir, here I am :-D

.

log AUCt

     90% CI

     PE=94.74%  [ 87.49% ... 102.59%] 



    Covariance Parameter Estimates



  Cov Parm     Subject    Group    Estimate



  Variance     subject              0.008436

  CS           subject              0.1875

  Residual     subject    tmt A     0.07150

  Residual     subject    tmt B     0.05300



NOTE: Convergence criteria met.

log AUCinf

     90% CI

     PE=95.30%  [ 88.32% ... 102.82%]  



    Covariance Parameter Estimates



  Cov Parm     Subject    Group    Estimate



  Variance     subject                    0 (!)

  CS           subject              0.1441

  Residual     subject    tmt A     0.07465

  Residual     subject    tmt B     0.06088



NOTE: Convergence criteria met.

NOTE: Estimated G matrix is not positive definite.

NOTE: Asymptotic variance matrix of covariance parameter estimates has been found to be singular and a generalized inverse was used. Covariance parameters with zero variance do not contribute to degrees of freedom computed by DDFM=SATTERTH.

Please note the 'Variance' parameter in case of AUCinf.
CS Covariance matrix parameterized in Proc MIXED as:

( CS+var  CS

  CS      CS+var)

See this post to notice that we really need 'Variance'=0 in our model (Type CS is only an approximation to that end, hoping the 'Variance' parameter is fitted with a value near zero).
So we eventually have the optimizer to tell that for AUCt. Couldn't figure out in a hurry at moment how to do that.

—
Regards,

Detlew

Complete thread:

FDA's HVD SAS Code from Progesterone Guidance jag009 2013-04-22 16:39 [RSABE / ABEL]
- 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. 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 opinion d_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