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RegisterSample Size and CV for Replicate Design [Power / Sample Size]
Hi JamesMartinn,
You should download Detlew Labes' R package called PowerTOST.
It will allow you to calculate the sample size (number of subjects) needed to achieve a given power under a set of assumptions and given a design. You have a 2-sequence, 4 period, 2 treatment design, and that's fairly common and easily handled by this package. You do not need to understand all the stats in order to use that tool.
This forum is a great resource. If you use the search function you will probably find discussions about relevant or related issues.
Good luck.
EM.
❝ I'm told that the intra-subject variability, expressed as %CV of a measured response is expected to be 35%. I'm asked to find the sample size in order to have 80% confidence that the estimated CV% is larger than 30%. Assume I'm planning to do a 2x4 Crossover, Replicate design. That is, I will be looking at TRTR and RTRT.
❝ I'm completely lost on how to approach the question. Any direction or guidance in answering this particular question will be much appreciated. I have access to SAS and R. Please advise.
You should download Detlew Labes' R package called PowerTOST.
It will allow you to calculate the sample size (number of subjects) needed to achieve a given power under a set of assumptions and given a design. You have a 2-sequence, 4 period, 2 treatment design, and that's fairly common and easily handled by this package. You do not need to understand all the stats in order to use that tool.
This forum is a great resource. If you use the search function you will probably find discussions about relevant or related issues.
Good luck.
EM.
Complete thread:
- Sample Size and CV for Replicate Design Jamesmartinn 2011-11-26 20:22 [Power / Sample Size]
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Sample Size and CV for Replicate DesignElMaestro 2011-11-26 22:38
- Sample Size and CV for Replicate Design Jamesmartinn 2011-11-26 23:52
- Sample Size and CV for Replicate Design ElMaestro 2011-11-27 00:43
- Sample Size and CV for Replicate Design Jamesmartinn 2011-11-27 00:50
- Sample Size and CV for Replicate Design ElMaestro 2011-11-27 01:24
- Sample Size and CV for Replicate Design Jamesmartinn 2011-11-27 01:50
- Strange questions… Helmut 2011-11-27 04:47
- Strange questions… Jamesmartinn 2011-11-27 14:43
- Misusing PowerTOST for superiority? Helmut 2011-11-27 17:46
- Strange questions… ElMaestro 2011-11-27 15:14
- Strange questions… Helmut 2011-11-27 18:07
- Strange questions… Jamesmartinn 2011-11-27 14:43
- Strange questions… Helmut 2011-11-27 04:47
- Sample Size and CV for Replicate Design Jamesmartinn 2011-11-27 01:50
- Sample Size and CV for Replicate Design ElMaestro 2011-11-27 01:24
- Sample Size and CV for Replicate Design Jamesmartinn 2011-11-27 00:50
- Sample Size and CV for Replicate Design ElMaestro 2011-11-27 00:43
- Sample Size and CV for Replicate Design Jamesmartinn 2011-11-26 23:52
- Sample Size and CV for Replicate DesignElMaestro 2011-11-26 22:38
Ing. Helmut Schütz