Bioequivalence and Bioavailability Forum • Less or More of an issue

Less or More of an issue [Regulatives / Guidelines]

posted by ElMaestro – Denmark, 2010-02-01 18:22 (5570 d 18:30 ago) – Posting: # 4687
Views: 23,966

Dear d_labes,

I think much of the confusion comes from the use of word "random".
It may lead to the impression that a model is fit with one or more random terms in addition to the error term, in other words, a mixed model. This is not the case.
When Proc GLM is executed it means in our context: "Fit a fixed effects model and do a standard anova". As pointed out this gives rise to a test of seq with the wrong error term.
When Proc GLM is executed with the proper bogus statement it means in our context "Fit a fixed effects model, and do an anova but when doing that make sure to do a proper calculation of P for the sequence effect".

I call it a bogus statement simply for linguistic reasons. It certainly makes sense to do what the statement does, but syntactically it is unfortunate that it is called "random" because it can lead the user to think (s)he is doing a mixed model fit.
If in any doubt, just leave out the bogus statement, get the normal anova and then do a posthoc correction for sequence effect with manual coding.

Best regards
EM.

Complete thread:

EMA BE guideline - final version Ohlbe 2010-01-28 18:31 [Regulatives / Guidelines]
- Final version published Helmut 2010-01-29 14:29
  - Final version published ElMaestro 2010-01-29 17:02
    - Statistix Helmut 2010-01-29 17:30
      - Statistix ElMaestro 2010-01-29 18:11
    - Calories ;-) Helmut 2010-01-29 19:22
      - Calories ;-) ElMaestro 2010-01-29 20:43
        
        Calories ;-) Helmut 2010-01-29 21:08
      - Variable calories d_labes 2010-02-01 12:05
    - ANOVA only - no doubts Helmut 2010-02-10 23:41
      - ANOVA only - no doubts ElMaestro 2010-02-12 21:09
  - Final EMA oracle d_labes 2010-02-01 11:53
    - Final EMA oracle Helmut 2010-02-01 12:28
    - Final EMA oracle ElMaestro 2010-02-01 12:50
      - More then two EMA oracles d_labes 2010-02-01 13:30
        
        Less of an issue ElMaestro 2010-02-01 15:29
        
        Less or More of an issue d_labes 2010-02-01 16:53
        
        Less or More of an issueElMaestro 2010-02-01 17:22
        
        Effective with 1 Aug 2010 Helmut 2010-02-02 00:55
        Bias? ElMaestro 2010-02-04 11:27
        
        Bias? Helmut 2010-02-05 02:03
        
        Bias? ElMaestro 2010-02-05 09:33
        
        Bias? Helmut 2010-02-05 10:21
        
        Bias? d_labes 2010-02-05 13:59
        Bias? ElMaestro 2010-02-05 16:00
        
        Bias? Helmut 2010-02-05 19:14
      - Final EMA oracle Helmut 2010-02-01 13:43
        
        Final EMA oracle ElMaestro 2010-02-01 14:54
        
        Final EMA oracle d_labes 2010-02-01 15:20
        
        Teaching Helmut 2010-02-01 16:07
  - Cmin really gone? tmax reappeared? d_labes 2010-02-01 14:02
    - Cmin really gone. tmax reappeared - but how? Helmut 2010-02-01 23:30
  - Interpol or not d_labes 2010-02-01 14:52
    - Interpol! Helmut 2010-02-02 00:02
      - Interpol! ray_be 2010-02-03 18:31
        
        WinNonlin/Phoenix extrapolation to t=tau Helmut 2010-02-03 20:26
  - Meta-analysis Helmut 2010-02-07 17:41
  - Final version published Panks.79 2010-03-08 07:22
    - Cmin for MR-formulations? Helmut 2010-03-08 18:16
      - Cmin for MR-formulations? Marcel 2010-04-23 10:09
        
        MR-Guideline? Helmut 2010-04-23 12:34
- Overview of comments published Helmut 2010-02-10 18:33
  - Comments commented d_labes 2010-02-11 08:19
  - Definition of Cmin by EMEA Ravi 2010-03-13 12:05
    - The EMA’s Cmin & WinNonlin Helmut 2010-03-13 12:52