udayk
☆    

India,
2020-03-06 09:00

Posting: # 21214
Views: 3,354
 

 Outlier Test using R-Software and Phoenix WinNonlin software in the BE [Outliers]

Dear All,

Please help us for outlier test using Phoenix WinNonlin Software (Studentized residual method) and R-Software (code) in the Bioequivalence 2way cross design.

Regards,
UdayK.


Edit: category changed and two successive posts merged [Ohlbe]
ping4santosh
☆    

India,
2020-03-11 14:58

@ udayk
Posting: # 21250
Views: 1,126
 

 Outlier Test using R-Software and Phoenix WinNonlin software in the BE

Hi Uday,

Please let me know more details. I can help you with outliers treatment.

Best,
SKM
Helmut
★★★
avatar
Homepage
Vienna, Austria,
2020-03-13 11:21

@ udayk
Posting: # 21267
Views: 1,086
 

 Studentized & standardized residuals

Hi UdayK,

» […] outlier test using Phoenix WinNonlin Software (Studentized residual method) and R-Software (code) in the Bioequivalence 2way cross design.

“Studentized residual” is an ambiguous term. There are two flavors:
  1. Internally studentized (aka “standardized”), where
    \(\widehat{\sigma}^2={1 \over n-m}\sum_{j=1}^n \widehat{\varepsilon\,}_j^{\,2}\)
  2. Externally studentized, where
    \(\widehat{\sigma}_{(i)}^2={1 \over n-m-1}\sum_{\begin{smallmatrix}j = 1\\j \ne i\end{smallmatrix}}^n \widehat{\varepsilon\,}_j^{\,2}\)
#1 is easily accessible in Phoenix WinNonlin (divide the raw residual by the standard error). Assess only the first period. The value of the other period has the same value but with the opposite sign and is therefore, not informative. No idea how to get #2 In WinNonlin. Ask at Certara’s forum.
Both are easily obtained in SAS, R,…

In R for the fixed effects model (untested!):

mod  <- lm(log(PK) ~ sequence + subject%in%sequence + period + treatment,
                     data = yourdata)
res1 <- rstandard(mod) # 1. Internally studentized (standardized)
res2 <- rstudent(mod)  # 2. Externally studentized

Note that #2 is in general more restrictive than #1, i.e., it might be that you detect more outliers.
BTW, which outlier test are you thinking of? See also there and this thread at stackoverflow.

Cheers,
Helmut Schütz
[image]

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ping4santosh
☆    

India,
2020-03-14 14:52

@ udayk
Posting: # 21269
Views: 1,027
 

 Outlier Test using R-Software: Lund test

Hi Uday,

Try Lund test in R package. If you want, I can help you out.

Cheers,
SKM
udayk
☆    

India,
2020-03-20 07:05

@ ping4santosh
Posting: # 21288
Views: 897
 

 Outlier Test using R-Software: Lund test

Hi SKM,

Please help us.

Regards,
Uday
ping4santosh
☆    

India,
2020-03-20 10:07
(edited by ping4santosh on 2020-03-21 03:37)

@ udayk
Posting: # 21289
Views: 886
 

 Outlier Test using R-Software: Lund test

» Please help us.

Hi Uday: I shall need access to the data and the background info. Cheers, SKM

NB: my email ID is my ID here in Gmail.
yjlee168
★★  
avatar
Homepage
Kaohsiung, Taiwan,
2020-03-20 14:45

@ udayk
Posting: # 21291
Views: 870
 

 bear for outlier detection analysis?

Hi udayk,

You may consider bear - an R package if you like. With bear, you can do outlier detection analysis (ODA) for a 2x2x2 BE study. Bear provides the following ODAs:
  1. Test for Normality (Pearson): studentized intra-subject residuals & studentized inter-subject residuals;
  2. Hotelling T2 with Chi-square Test;
  3. Test for Equality of Intra-subject Variabilities between Formulations; and
  4. Cook's distance.
For more info, please see my signature panel.

[image]

All the best,
-- Yung-jin Lee
bear v2.8.7:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan http://pkpd.kmu.edu.tw/bear
Download link (updated) -> here
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