Bioequivalence and Bioavailability Forum • FA0(1) for partial replicate in Phoenix

FA0(1) for partial replicate in Phoenix [RSABE / ABEL]

posted by Helmut – Vienna, Austria, 2013-08-07 15:13 – Posting: # 11235
Views: 6,696

Dear Detlew!

» Will try it the next time numerically.

Yes please. I tried John’s nasty data set (log-transformed data in full precision) where we ran into convergence problems and got different results for RSABE and ABE (we tried SAS and PHX; complete data set and after exclusion of incomplete data).
When I set up FA0(1) in PHX’ LME I got…
ERROR 11021: Variance matrix is not positive definite in QA.
… which is an indication that the initial variance estimates (by methods of moments) don’t “work”. I tried different starting values to no avail.

Now for the surprise: PHX’ BE-model (which supposedly sits ‘on top’ of LME) converged without a warning. I got

PE 101.0213% (90% CI: 80.7733–126.3450%) s²_WR 0.42100 (CV_WR 72.35%)

… matching Shuanghe’s and your’s in SAS with FDA’s FA0(2)-parameterization.
After exclusion of incomplete data (subjects 8, 14, 17, and 31)

PE 91.2423% (90% CI: 74.0705–112.3950%) s²_WR 0.40652 (CV_WR 70.82%)

… different to yours’.
Amazing.

—
Cheers,
Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. ☼
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Complete thread:

RSAB model overspecified Wolfgang 2013-08-05 14:37 [RSABE / ABEL]
- RSAB model overspecified jag009 2013-08-05 15:35
- Proc Mixed FA0(1) for partial replicate d_labes 2013-08-05 15:59
  - Proc Mixed FA0(1) for partial replicate Wolfgang 2013-08-05 16:24
    - Proc Mixed FA0(1) for partial replicate ElMaestro 2013-08-05 17:19
      - Proc Mixed FA0(1) for partial replicate Wolfgang 2013-08-06 08:35
        
        Proc Mixed FA0(1) for partial replicate ElMaestro 2013-08-06 10:34
    - Proc Mixed FA0(1) for partial replicate d_labes 2013-08-06 10:30
      - FA0(1) for partial replicate in Phoenix Helmut 2013-08-07 15:13
        
        FA0(1) for partial replicate in SAS d_labes 2013-08-08 09:42
        FA0(1) for partial replicate in Phoenix lhughes 2013-08-30 15:17
        
        FA0(1) in PHX: works (& more questions) Helmut 2013-08-30 17:07