udayk
☆

India,
2020-03-06 10:00
(1302 d 07:28 ago)

Posting: # 21214
Views: 6,013

## 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 15:58
(1297 d 01:30 ago)

@ udayk
Posting: # 21250
Views: 3,519

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

Hi Uday,

Best,
SKM
Helmut
★★★

Vienna, Austria,
2020-03-13 12:21
(1295 d 05:07 ago)

@ udayk
Posting: # 21267
Views: 3,433

## 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.

Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
ping4santosh
★

India,
2020-03-14 15:52
(1294 d 01:35 ago)

@ udayk
Posting: # 21269
Views: 3,401

## 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 08:05
(1288 d 09:22 ago)

@ ping4santosh
Posting: # 21288
Views: 3,264

## Outlier Test using R-Software: Lund test

Hi SKM,

Regards,
Uday
ping4santosh
★

India,
2020-03-20 11:07
(1288 d 06:20 ago)

(edited by ping4santosh on 2020-03-21 03:37)
@ udayk
Posting: # 21289
Views: 3,182

## Outlier Test using R-Software: Lund test

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
★★★

Kaohsiung, Taiwan,
2020-03-20 15:45
(1288 d 01:42 ago)

@ udayk
Posting: # 21291
Views: 3,200

## 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.

All the best,
-- Yung-jin Lee
bear v2.9.1:- created by Hsin-ya Lee & Yung-jin Lee
Kaohsiung, Taiwan https://www.pkpd168.com/bear