junhao
☆    

China,
2016-04-18 12:15
(2901 d 05:20 ago)

Posting: # 16210
Views: 7,620
 

 The Diletti reference on sample size determination [Power / Sample Size]

Dear All,

I see everybody is refering this famous reference but where exactly can I find or buy it? I searched in the forum and google for hours but failed anyway to find the full-text reference. Does anyone really have this full-text reference at hand? Could you share where and how you get it? Appreciate it so much!

Diletti E, Hauschke D and VW Steinijans
Sample size determination for bioequivalence assessment by means of confidence intervals
Int J Clin Pharm Ther Toxicol 29(1), 1–8 (1991)

Best regards,
Junhao//
Helmut
★★★
avatar
Homepage
Vienna, Austria,
2016-04-18 15:22
(2901 d 02:12 ago)

@ junhao
Posting: # 16211
Views: 6,689
 

 PowerTOST?

Hi Junhao,

you can try to get it from the the Publishers (Dustri-Verlag, contact Petra Estner). Alternatively you could ask Dieter Hauschke for a copy.
If that doesn’t work I can scan my copy (will be lousy: yellowed and with notes in the margins…).
It is a very interesting paper if you want to understand the background of sample size estimation. For practical use less so. The tables are for 70/80/90% power, T/R-ratios of 0.85–1.20 (step size 0.05), and CVs of 5–30% (step size 2.5%). Power curves are highly nonlinear. If you want anything which is not covered in the tables, interpolation is not a good idea.
If you want to estimate sample sizes for any desired power, ratio, and CV I recommend the package PowerTOST for R (freeware!). In PowerTOST many designs are covered (two parallel groups, paired means, crossovers: 2×2×2, 3×3, 3×6×3, replicates: 2×2×4, 2×2×3, 2×4×4, partial 2×3×3, Balaam’s 2×4×2, Liu’s 2×2×2). Additionally to power / sample size for conventional average bioequivalence other methods are supported: Reference-scaling for HVD(P)s according to the FDA’s, EMA’s, and ANVISA’s requirements; RSABE for NTIDs (FDA); noninferiority, ratio of means (Fieller’s CI), dose proportionality (power model). Check out the online-manual.

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

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

Berlin, Germany,
2016-04-18 21:28
(2900 d 20:07 ago)

@ Helmut
Posting: # 16214
Views: 6,401
 

 freeware != free (open source) software

Dear Helmut, dear Junhao!

❝ ... If you want to estimate sample sizes for any desired power, ratio, and CV I recommend the package PowerTOST for R (freeware!).


[nitpicking]

R is free software which comes with source code (open source). Package PowerTOST also.
That's distinct from freeware.
But that is of course an only puristic note or for lawyers dealing with licenses :cool:.

[/nitpicking]

BTW: @Helmut what's that 'Hero' below my user name in the post pane?

Regards,

Detlew
Helmut
★★★
avatar
Homepage
Vienna, Austria,
2016-04-19 02:03
(2900 d 15:32 ago)

@ d_labes
Posting: # 16215
Views: 6,368
 

 Hero

Dear Detlew,

[nitpicking]

❝    free software

[/nitpicking]


Oops, correct!

❝ BTW: @Helmut what's that 'Hero' below my user name in the post pane?


Hover over it. It categorizes members by their number of contributions. Only four others reached the level you are in… :thumb up:

I don’t care to belong to any club that will have me as a member.   Groucho Marx

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

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

Berlin, Germany,
2016-04-19 11:14
(2900 d 06:21 ago)

@ Helmut
Posting: # 16219
Views: 6,336
 

 Hero

Dear Helmut,

I don’t care to belong to any club that will have me as a member.   Groucho Marx


Full ACK :cool:

Regards,

Detlew
junhao
☆    

China,
2016-04-19 07:37
(2900 d 09:58 ago)

@ d_labes
Posting: # 16218
Views: 6,466
 

 freeware != free (open source) software

Dear Detlew,

R is free software which comes with source code (open source). Package PowerTOST also.

❝ That's distinct from freeware.

❝ But that is of course an only puristic note or for lawyers dealing with licenses :cool:.


Thank you for letting me know the difference :-D
And I am surprised to recognize that you must also be one of the authors of the R package! I love you heroes so much for making such amazing tools! :clap:

Best regards,

Junhao//
d_labes
★★★

Berlin, Germany,
2016-04-19 11:54
(2900 d 05:41 ago)

@ junhao
Posting: # 16220
Views: 6,259
 

 PowerTOST authors

Dear Junhao,

❝ And I am surprised to recognize that you must also be one of the authors of the R package ...


Too bad that this well-kept secret now is disclosed :-D.
I'm in respectable society. Try in R:

library(PowerTOST)
citation(package="PowerTOST")


Remember the guy called 'Maintainer' in the DESCRIPTION file if you encounter problems in trying PowerTOST.

Regards,

Detlew
junhao
☆    

China,
2016-04-19 07:26
(2900 d 10:09 ago)

@ Helmut
Posting: # 16216
Views: 6,408
 

 PowerTOST?

Dear Helmut,

❝ you can try to get it from the the Publishers (Dustri-Verlag, contact Petra Estner). Alternatively you could ask Dieter Hauschke for a copy.


Thank you for your quick reply and kind offer! I thought the paper would be an interesting and important one to help me understand the background of sample size estimation and the whole statistical considerations of BE testing. I will follow what you have told me, try to ask Petra Estner and Dieter Hauschke first for a copy. I will also try the PowerTOST in R later and I appreciate you as one of the authors of the R package!

Thank you for your help again Helmut and all the best,

Junhao//
UA Flag
Activity
 Admin contact
22,957 posts in 4,819 threads, 1,638 registered users;
73 visitors (0 registered, 73 guests [including 8 identified bots]).
Forum time: 16:35 CET (Europe/Vienna)

Nothing shows a lack of mathematical education more
than an overly precise calculation.    Carl Friedrich Gauß

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5