Bioequivalence and Bioavailability Forum • FDA’s model…

FDA’s model… [Software]

posted by Helmut – Vienna, Austria, 2014-10-09 20:34 (3910 d 05:33 ago) – Posting: # 13683
Views: 39,138

Dear Yung-jin,

❝ […] it is not caused by "reaching its max. iterations..." as lme().

Exactly.

❝ Is there any random effect or are all effects fixed in model for this situation? Could you try with all effects fixed to see if it can be improved?

Nope. I happens (only for some nasty datasets) in a partial replicate design (full replicates are OK) if following FDA’s mixed effects model for ABE:

PROC MIXED data=pk; CLASSES SEQ SUBJ PER TRT; MODEL LAUCT = SEQ PER TRT/ DDFM=SATTERTH; RANDOM TRT/TYPE=FA0(2) SUB=SUBJ G; REPEATED/GRP=TRT SUB=SUJ; ESTIMATE 'T vs. R' TRT 1 -1/CL ALPHA=0.1; ods output Estimates=unsc1; title1 'unscaled BE 90% CI - guidance version'; title2 'AUCt'; run; data unsc1; set unsc1; unscabe_lower=exp(lower); unscabe_upper=exp(upper); run;

The problem lies in the random section where the structure of the covariance structure is specified with TYPE=FA0(2). CSH or FAO(1) helps. I don’t see how to go with ‘all fixed effects’ here…

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Helmut Schütz

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Complete thread:

reference dataset elba.romero 2013-07-02 05:08 [Software]
- Public datasets Helmut 2013-07-02 15:44
  - Public datasets yjlee168 2013-07-03 03:10
    - Public datasets elba.romero 2013-07-03 05:19
      - Public datasets yjlee168 2013-07-03 13:11
        
        Challenging data sets Helmut 2013-07-03 16:32
        
        Fantastic idea? ⇒ Challenging data sets yjlee168 2013-07-04 08:06
        
        Fantastic idea! Helmut 2013-07-04 13:18
    - NIST; cross-validation Helmut 2013-07-03 14:28
      - NIST; cross-validation yjlee168 2013-07-03 23:47
        
        NIST; cross-validation Helmut 2013-07-04 00:45
  - Public datasets elba.romero 2013-07-03 05:10
- Eight Reference Datasets (2×2×2 ☑) Helmut 2014-10-06 02:24
  - What??? ElMaestro 2014-10-06 13:20
    - What??? Helmut 2014-10-06 17:08
      - What??? ElMaestro 2014-10-06 17:31
        
        What the heck‽ Helmut 2014-10-06 19:05
  - link of electronic supplement material? yjlee168 2014-10-07 09:53
    - link of electronic supplement material? nobody 2014-10-07 10:59
      - Thanks! yjlee168 2014-10-07 11:35
        
        Thanks! nobody 2014-10-07 11:44
        
        Direct links & hint Helmut 2014-10-07 13:54
    - Replicated designs are relevant, too ElMaestro 2014-10-07 12:36
      - Replicated designs are relevant, too yjlee168 2014-10-07 13:00
        
        RSABE: SAS and PHX/WNL only? Helmut 2014-10-07 14:47
        
        for the future? yjlee168 2014-10-08 10:05
        
        Star Trek: The Next Generation Helmut 2014-10-09 00:26
        
        Star Trek: The Next Generation d_labes 2014-10-09 08:09
        Star Trek: The Next Generation nobody 2014-10-09 08:23
        Star Trek: The Next Generation yjlee168 2014-10-09 11:06
        
        Some comments ElMaestro 2014-10-09 11:52
        
        Some comments yjlee168 2014-10-09 12:18
        
        Proc MIXED - start value d_labes 2014-10-10 08:35
        
        Proc MIXED - start value ElMaestro 2014-10-10 11:44
        Proc MIXED - start value yjlee168 2014-10-11 21:09
        
        Proc MIXED - start value ElMaestro 2014-10-11 21:18
        
        Optimizer settings Helmut 2014-10-09 14:08
        
        Optimizer settings nobody 2014-10-09 15:32
        Optimizer settings yjlee168 2014-10-09 18:14
        
        FDA’s model…Helmut 2014-10-09 18:34
  - Just received a letter… Helmut 2014-11-03 14:54
  - 11 Reference Datasets (2-group parallel ☑) Helmut 2014-12-09 15:51