Bioequivalence and Bioavailability Forum

BE-proff ● 2016-04-06 23:39 (3273 d 05:56 ago) Posting: # 16167 Views: 10,136	PowerTOST for steady state [🇷 for BE/BA] Post reply
	Hi All, Is it possible to calculate number of subjects for steady state study with PowerTOST? What parameters are required? Edit: Category changed. [Helmut]

d_labes
★★★

Berlin, Germany,
2016-04-07 12:54
(3272 d 16:41 ago)

@ BE-proff
Posting: # 16168
Views: 9,034

PowerTOST for steady state

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Dear BE-proff,

❝ Is it possible to calculate number of subjects for steady state study with PowerTOST? :confused:

Of course, it's the Gold Standard :-D

❝ What parameters are required?

The same as for sample size estimation for other types of BE studies.

An educated guess of the variability of your primary targets (usually AUC_tau and C_max,ss in case of steady state studies)
target power (>=80% usually), alpha (0.05 usually)
'True' GMR for which power should be calculated (usually set to 0.95 if no other information is available)
design of the study

Thats all. More arguments of the sample size estimation functions in PowerTOST you may find in the man pages. These are more or less only for special purposes.

—
Regards,

Detlew

BE-proff ● 2016-04-07 17:42 (3272 d 11:53 ago) @ d_labes Posting: # 16171 Views: 8,907	PowerTOST for steady state Post reply
	Hi d_labes, Could you share a sample of script for calculation? How to write design type in it?

Helmut
★★★

Vienna, Austria,
2016-04-07 18:09
(3272 d 11:25 ago)

@ BE-proff
Posting: # 16172
Views: 8,932

RTFM

Post reply

H BE-proff,

❝ Could you share a sample of script for calculation?

As Detlew wrote above

❝ ❝ More arguments of the sample size estimation functions in PowerTOST you may find in the man pages.

Type help(package=PowerTOST) in the R-console or use the online-version. Most interesting functions are sampleN.TOST() for ABE, sampleN.scABEL() for the EMA’s ABEL, and sampleN.RSABE() for the FDA’s RSABE.
At the end of all man pages you will find examples.

❝ How to write design type in it? :confused:

RTFM (argument design) of the sampleN-functions:

sampleN.TOST
Character string describing the study design.
See known.designs() for designs covered in this package.
sampleN.scABEL and sampleN.RSABE
Design of the study to be planned.
2x3x3 is the partial replicate design (TRR|RTR|RRT).
2x2x3 is the 3-period replicate design (TRT|RTR).
2x2x4 is the full replicate design with 2 sequences and 4 periods.
Defaults to design="2x3x3"

Get others from known.designs(). The column design shows the argument to specify in the functions (e.g., design="2x2x2" or design="parallel").

—
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

BE-proff
●

2016-04-09 22:15
(3270 d 07:19 ago)

@ Helmut
Posting: # 16176
Views: 8,788

RTFM

Post reply

Hi Helmut,

I have tried to enter known.designs() and it returned the following list:

1            2 parallel groups

2                2x2 crossover

3              2x2x2 crossover

4                3x3 crossover

5              3x6x3 crossover

6                4x4 crossover

7    2x2x3 replicate crossover

8    2x2x4 replicate crossover

9    2x4x4 replicate crossover

10   partial replicate (2x3x3)

11            Balaam's (2x4x2)

12 Liu's 2x2x2 repeated x-over

13                paired means

Where is my so wanted steady state design? :-)

Helmut
★★★

Vienna, Austria,
2016-04-10 02:50
(3270 d 02:45 ago)

@ BE-proff
Posting: # 16177
Views: 8,661

RTFM‼

Post reply

BE-proff,

❝ Where is my so wanted steady state design? :-)

Are you a troll? You estimate the sample sample for the PK metrics of interest (see this post) and the values Detlew stated already above. Only you know which design you will use! Plug the argument in one of PowerTOST’s functions. What’s your problem‽

—
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

BE-proff
●

2016-04-10 15:42
(3269 d 13:53 ago)

@ Helmut
Posting: # 16178
Views: 8,626

RTFM‼

Post reply

Hi Helmut,

I am not a troll :)
Below is a TOST example for calculation of parallel design study.

sampleN.TOST(CV=0.23, design="parallel")



+++++++++++ Equivalence test - TOST +++++++++++

            Sample size estimation

-----------------------------------------------

Study design:  2 parallel groups 

log-transformed data (multiplicative model)



alpha = 0.05, target power = 0.8

BE margins        = 0.8 ... 1.25

Null (true) ratio = 0.95,  CV = 0.23



Sample size (total)

 n     power

46   0.802730

What word must be written instead of "parallel" for calculate sample for steady state study?

Helmut
★★★

Vienna, Austria,
2016-04-10 15:48
(3269 d 13:46 ago)

@ BE-proff
Posting: # 16179
Views: 8,644

RTFM‼

Post reply

Hi BE-proff,

how shall I know in which design you plan to perform the steady state study?

❝ What word must be written instead of "parallel" for calculate sample for steady state study?

Heck, a steady state study can be done in any of the designs given by known.designs()!
If it’s not a parallel but a simple crossover use design="2x2x2". If it’s a four-period full replicate use design="2x2x4", et cetera, ad libitum, ad nauseam.

—
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

BE-proff ● 2016-04-12 15:36 (3267 d 13:59 ago) @ Helmut Posting: # 16186 Views: 8,486	RTFM‼ Post reply
	Hi Helmut, Yes! Now it is clear to me! Many thanks for your help and patience.

PowerTOST for steady state [🇷 for BE/BA]

PowerTOST for steady state

PowerTOST for steady state

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