Bioequivalence and Bioavailability Forum • Winnonlin: exclude incomplete data!

Winnonlin: exclude incomplete data! [Software]

posted by Helmut – Vienna, Austria, 2014-01-10 14:41 (4553 d 10:51 ago) – Posting: # 12155
Views: 19,890

Hi mittyri,

❝ ❝ […] Since Phoenix/WinNonlin only speaks REML, you have to exclude incomplete data. […] you have to filter for complete data in Phoenix first. Otherwise you are in mixed-effects model limbo.

❝

❝ In the study we have 2 volunteers who were discontinued the study after 1st period (both from same sequence)

❝ Do I understand correct, that I shouldn't put the data from these subjects to WNL?

Yes. See also the EMA’s GL:

[…] subjects in a crossover trial who do not provide evaluable data for both of the test and reference products […] should not be included.

❝ I tried both options (with and without them) and recieved unequal CIs

Correct. PHX/WNL in its default setting (incomplete data included) will recover information of the between-subject variance (REML estimate of a mixed-effects model). In SAS-speak that’s Proc MIXED instead of Proc GLM. In other words, the variance will be differently split into their between-, within-, and residual components. Therefore, the CI (and CV_intra) will be affected as well – though in my experience the difference generally is quite small.
See also an example in SAS 9.2 and WinNonlin 5.2.1.

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Complete thread:

SAS vs Winnonlin jag009 2013-07-24 17:30 [Software]
- SAS vs Winnonlin Helmut 2013-07-24 17:55
  - SAS vs Winnonlin jag009 2013-07-24 22:56
    - SAS vs Winnonlin Helmut 2013-07-24 23:53
      - SAS vs Winnonlin jag009 2013-07-25 00:56
        
        EMA crippled approach d_labes 2013-07-25 09:13
        
        Hypothesis jag009 2013-07-25 15:38
        
        Two at a Time? Or All at Once? Helmut 2013-08-10 13:52
        
        Heteroscedasticity Helmut 2013-07-27 18:30
  - Update! jag009 2013-07-27 05:59
    - Rounding limbo? Helmut 2013-07-27 14:53
      - Rounding limbo? jag009 2013-07-27 22:02
  - Winnonlin: exclude volunteers mittyri 2014-01-10 08:05
    - Winnonlin: exclude incomplete data!Helmut 2014-01-10 13:41
- SAS vs Winnonlin ElMaestro 2013-07-24 18:06
  - SAS vs Winnonlin jag009 2013-07-24 22:59