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RegisterPower of two combined TOST [General Statistics]
Dear Louis,
have a loook at this post or this one.
As our ElMaestro already said: According to the intersection-union principle there is no need for adjusting alpha if you combine two TOST with AND. As long as the two combined test on their own have size alpha.
Power is another pair of shoes.
If the correlation is zero, the overall power is the product of the powers of the individual tests, i.e. may be considerable lower then the targeted power.
If the correlation is one, the overall power is the minimum of the powers of the individual tests. This is the foundation why we make a sample size calculation for both metrics and choose the resulting higher sample size.
But no one knows, at least not me, to what number the correlation should be set in practice.
The authors team of the R package
Be aware: It is not the correlation of the two PK metrics itself. To cite from the man page of function
"rho: Correlation between the two PK metrics (e.g. AUC and Cmax) under consideration. This is defined as correlation between the estimator of the treatment difference of PK metric one and the estimator of the treatment difference of PK metric two."
Be further aware: The functions for power and sample size for the combination of 2 TOST are currently under revision since the implemented versions in V1.4-6 came out as statistical flawed. You need the development version of PowerTOST to get reliable values for the power of 2 TOST. See this thread how to get it.
Reference to look into:
Phillips KF.
Power for Testing Multiple Instances of the Two One-Sided Tests Procedure
Int J Biostat. 2009;5(1):Article 15. doi:10.2202/1557-4679.1169
❝ Can anyone direct me towards a thread where it is discussed/presented how to deal with alpha adjustment and power in case of multiplicity (AUC and Cmax considered at the same time)? Both CO and Parallel designs.
have a loook at this post or this one.
As our ElMaestro already said: According to the intersection-union principle there is no need for adjusting alpha if you combine two TOST with AND. As long as the two combined test on their own have size alpha.
Power is another pair of shoes.
If the correlation is zero, the overall power is the product of the powers of the individual tests, i.e. may be considerable lower then the targeted power.
If the correlation is one, the overall power is the minimum of the powers of the individual tests. This is the foundation why we make a sample size calculation for both metrics and choose the resulting higher sample size.
But no one knows, at least not me, to what number the correlation should be set in practice.
The authors team of the R package
PowerTOST is currently discussing that theme. May be we came out with some aid in the near future.Be aware: It is not the correlation of the two PK metrics itself. To cite from the man page of function
power.2TOST():"rho: Correlation between the two PK metrics (e.g. AUC and Cmax) under consideration. This is defined as correlation between the estimator of the treatment difference of PK metric one and the estimator of the treatment difference of PK metric two."
Be further aware: The functions for power and sample size for the combination of 2 TOST are currently under revision since the implemented versions in V1.4-6 came out as statistical flawed. You need the development version of PowerTOST to get reliable values for the power of 2 TOST. See this thread how to get it.
Reference to look into:
Phillips KF.
Power for Testing Multiple Instances of the Two One-Sided Tests Procedure
Int J Biostat. 2009;5(1):Article 15. doi:10.2202/1557-4679.1169
—
Regards,
Detlew
Regards,
Detlew
Complete thread:
- Power and type I adjustment for 222BE when several PK prams considered Louis52 2018-02-07 21:04 [General Statistics]
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Power and type I adjustment for 222BE when several PK prams considered ElMaestro 2018-02-07 22:37
- Power of two combined TOSTd_labes 2018-02-08 14:12
- The mysterious ρ Helmut 2018-02-08 21:40
- ρ ρ ρ your boat ElMaestro 2018-02-09 09:58
- ρ ρ ρ your boat Helmut 2018-02-09 19:20
- ...and a bonus question ElMaestro 2018-02-09 11:32
- ...and a bonus question Helmut 2018-02-09 19:43
- If u see a BEar don't forget to R oaρ Astea 2018-02-09 20:47
- package install failed d_labes 2018-02-11 13:23
- If u see a BEar don't forget to R oaρ Astea 2018-02-09 20:47
- ...and a bonus question Helmut 2018-02-09 19:43
- The mysterious ρ -between or within studies d_labes 2018-02-11 15:57
- The mysterious ρ -between or within studies Helmut 2018-02-11 17:31
- The mysterious ρ -between or within studies d_labes 2018-02-11 19:21
- The mysterious ρ within studies Helmut 2018-02-11 22:44
- The mysterious ρ within studies nobody 2018-02-12 09:08
- The mysterious ρ within studies Helmut 2018-02-11 22:44
- The mysterious ρ -between or within studies d_labes 2018-02-11 19:21
- The mysterious ρ -between or within studies Astea 2018-02-11 17:34
- The mysterious ρ -between or within studies d_labes 2018-02-11 19:36
- The mysterious ρ within studies Helmut 2018-02-11 22:48
- The mysterious ρ -between or within studies Helmut 2018-02-11 17:31
- ρ ρ ρ your boat ElMaestro 2018-02-09 09:58
- The mysterious ρ Helmut 2018-02-08 21:40
- Power and type I adjustment for 222BE when several PK prams considered ElMaestro 2018-02-11 18:43
- Power and type I adjustment for 222BE when several PK prams considered nobody 2018-02-12 09:10
- reminds me of something ElMaestro 2018-02-12 09:18
- reminds me of something nobody 2018-02-12 09:38
- Hammer to fall Astea 2018-02-12 18:37
- Put the sickle to the corn Helmut 2018-02-13 01:37
- Put the sickle to the corn Astea 2018-02-13 08:27
- Put the sickle to the corn Helmut 2018-02-13 12:45
- Put the sickle to the corn Relaxation 2018-02-13 10:37
- multiple units, lag-times Helmut 2018-02-13 13:31
- Put the sickle to the corn Astea 2018-02-13 08:27
- Put the sickle to the corn Helmut 2018-02-13 01:37
- Hammer to fall Astea 2018-02-12 18:37
- reminds me of something nobody 2018-02-12 09:38
- reminds me of something ElMaestro 2018-02-12 09:18
- Power and type I adjustment for 222BE when several PK prams considered nobody 2018-02-12 09:10
Ing. Helmut Schütz