## Regulatory acceptance of PowerTOST [Software]

Hi BE-proff,

» In Russia we have two options to prove sample size: either demonstrate calculations with formulas …

See this presentation (slide 8). The procedure is

» … or provide literature reference.

What do you mean by that?

» The 1st option is not for me because I don't have relevant background so I'd prefer the 2nd way.

»

» So, if somebody could share any literature reference in a journal (preferrable) which mentions PowerTOST I'd really appreciate it

Jones & Kenward

PowerTOST is mentioned in Nadarajah

In the folder

» In Russia we have two options to prove sample size: either demonstrate calculations with formulas …

See this presentation (slide 8). The procedure is

*always*iterative (since the*t*-value in the formula to calculate power depends on the degrees of freedom and hence, the sample size itself). The approximation^{1}by the shifted central*t*-distribution can be done with a pocket calculator (alternatively: paper-pencil-brain) and a*t*-table. The better approximation (noncentral*t*) already needs software, since no tables exist for a range of the noncentrality parameter. The exact method needs numeric integration of two integrals → software.» … or provide literature reference.

What do you mean by that?

» The 1st option is not for me because I don't have relevant background so I'd prefer the 2nd way.

»

» So, if somebody could share any literature reference in a journal (preferrable) which mentions PowerTOST I'd really appreciate it

Jones & Kenward

^{2}The power and sample size for a bioequivalence trial can conveniently be calculated using the R package PowerTOST (Labes (2013)).^{a}

The power is calculated using the R package PowerTOST (Labes (2013)) with the “exact” option.^{b}

Using the PowerTOST (Labes (2013)) R library function, the power, for a true ratio of 1, for this estimated CV and a total sample size of 20 is just over 0.04.^{c}

PowerTOST is mentioned in Nadarajah

*et al.*^{3}In the folder

`\library\PowerTOST\tests`

you find R-scripts to validate the various sample size functions against published data. See the man-pages of `ct5.1`

, `ct5.2`

, `ct5.3`

, `ct5.4.1`

, `ct9.6.2`

, `ct9.6.4`

, `ct9.6.6`

, `ct9.6.8`

, `ctCW.III`

, `ctSJ.VIII.10`

, and `ctSJ.VIII.20`

for the references.- Hauschke, D, Steinijans, VW, Diletti E, Burke M.
*Sample Size Determination for Bioequivalence Assessment Using a Multiplicative Model.*

J Pharmacokin Biopharm 1992;20(5);557–61. doi:10.1007/BF01061471.

- Jones B, Kenward MG.
*Design and Analysis of Cross-Over Trials.*

Boca Raton: CRC Press / Chapman & Hall; 3^{rd}ed. 2015.- p.329

- p.373

- p.379

- p.329
- Nadarajah S, Sergey Bityukov S, Krasnikov N.
*Confidence distributions: A review*.

Stat Meth. 2015;22:23–46. doi:10.1016/j.stamet.2014.07.002. open source.

—

Cheers,

Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮

Science Quotes

Cheers,

Helmut Schütz

The quality of responses received is directly proportional to the quality of the question asked. 🚮

Science Quotes

### Complete thread:

- Regulatory acceptance of PowerTOST BE-proff 2016-06-02 14:35 [Software]
- Regulatory acceptance of Sample size software d_labes 2016-06-02 15:05
- PowerTOST/Power2Stage: no issues so far Helmut 2016-06-02 15:39
- Regulatory acceptance of PowerTOST DavidManteigas 2016-06-03 11:05
- Regulatory acceptance of PowerTOST BE-proff 2016-06-03 22:30
- Regulatory acceptance of PowerTOSTHelmut 2016-06-04 15:51
- Regulatory acceptance of PowerTOST BE-proff 2016-06-07 15:15

- Regulatory acceptance of PowerTOSTHelmut 2016-06-04 15:51

- Regulatory acceptance of PowerTOST BE-proff 2016-06-03 22:30
- Regulatory acceptance of PowerTOST ElMaestro 2016-06-04 16:12
- Regulatory acceptance of PowerTOST BE-proff 2016-06-07 15:17
- Regulatory acceptance of PowerTOST mittyri 2016-06-08 07:51
- Regulatory acceptance of PowerTOST Astea 2016-06-14 17:41

- Regulatory acceptance of PowerTOST mittyri 2016-06-08 07:51

- Regulatory acceptance of PowerTOST BE-proff 2016-06-07 15:17