Bioequivalence and Bioavailability Forum • Negative variance component

Negative variance component [Software]

posted by yjlee168 – Kaohsiung, Taiwan, 2014-01-31 11:26 (4506 d 13:47 ago) – Posting: # 12302
Views: 32,841

Dear all,

Sorry to cut in. Yes, non-estimable CV_inter could happen, I guess. In bear, we had a dataset for demo run purpose (single-dose, 2x2x2 design; and the dataset can be obtained from the top menu of bear ('Generate/export all demo datatsets'; it's called 'Single2x2x2_demo.csv' or 'Single2x2x2_demo.RData'.) ln(Cmax) is OK, but for ln(AUC_0-t) and ln(AUC_0-inf), we got

for ln(AUC_0-t)...

Intra_subj. CV = 100*sqrt(exp(MSResidual)-1) = 18.392 %

Inter_subj. CV = 100*sqrt(exp((MSSubject(seq)-MSResidual)/2)-1)

               =  NaN %

    MSResidual = 0.0332664 

MSSubject(seq) = 0.02123317 ...

and

for ln(AUC_0-inf)...

Intra_subj. CV = 100*sqrt(exp(MSResidual)-1) = 17.788 %

Inter_subj. CV = 100*sqrt(exp((MSSubject(seq)-MSResidual)/2)-1)

               =  NaN %

    MSResidual = 0.03114947 

MSSubject(seq) = 0.01895625  ...

Happy Chinese Lunar New Year (today)!

❝ ...for PHX:

❝ if(Hypothesis = 'Sequence*Subject', 100*sqrt(exp((MS-MSerror)/2)-1), ''), in my data MS is smaller than MSerror hence the resultant number before taking last step squareroot becomes negative.

—
All the best,
-- Yung-jin Lee
bear v2.9.6:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear
Download link (updated) -> here

Complete thread:

How to calculate intersubject variability in PHX WinNonlin zan 2014-01-29 23:58 [Software]
- Negative variance component Helmut 2014-01-30 01:16
  - Negative variance component zan 2014-01-30 18:11
  - Negative variance component zan 2014-01-31 00:16
    - Negative variance component ElMaestro 2014-01-31 08:20
    - Negative variance componentyjlee168 2014-01-31 10:26
      - Example data set Helmut 2014-02-01 16:03
        
        Example data set yjlee168 2014-02-01 17:40
        
        PHX build 6.3.0.395 / 6.4.0.511 Helmut 2014-02-02 02:04
        
        PHX build 6.3.0.395 / 6.4.0.511 yjlee168 2014-02-02 07:54
    - Negative variance component ElMaestro 2014-02-01 16:31
      - Negative variance component yjlee168 2014-02-01 17:47
        
        Just thinking loud ElMaestro 2014-02-01 19:02
        
        All models are wrong… Helmut 2014-02-02 02:31
        
        another book for linear model yjlee168 2014-02-02 08:07
      - References Helmut 2014-02-02 02:19
        
        References ElMaestro 2014-02-02 09:56
    - Negative variance component – Chow/Liu d_labes 2014-02-03 09:02
      - Negative variance component – Chow/Liu ElMaestro 2014-02-03 10:22
        
        Variance components – Proc mixed d_labes 2014-02-03 11:58
        
        Variance components – Proc mixed ElMaestro 2014-02-03 12:58
        
        Variance components – Proc mixed 90% CIs d_labes 2014-02-03 13:16
        Variance components – Proc mixed Helmut 2014-02-03 14:14
        
        FDA code for non-replicate crossover? d_labes 2014-02-03 15:54
        
        Proc GLM rulez Helmut 2014-02-03 16:16
        
        Variance components – Proc mixed yjlee168 2014-02-03 20:43
        
        NOBOUND Helmut 2014-02-03 22:08
      - lm() or lme() for 2x2x2 study design? yjlee168 2014-02-03 20:22
        
        lm() or lme() for 2x2x2 study design? ElMaestro 2014-02-03 22:11
        
        lm() or lme() for 2x2x2 study design? yjlee168 2014-02-04 13:09
        
        bear for 2x2x2 study with negative variance components yjlee168 2014-02-05 19:12