Fieller’s (‘fiducial’) confidence interval [General Statistics]
Dear ElMaestro,
» For such cases we are setting
Correct in so far if we use the approximation that the estimate of µR is (statistically) greater than zero. A very reasonable assumption for the usual metrics AUC and Cmax IMHO.
But this has than nothing to do with Fieller’s (‘fiducial’) confidence interval, a more correct method for deriving a confidence interval for the ratio of untransformed PK metrics.
PowerTOST has for this case the functions
Have a look into the man pages of these functions and notice that these functions don't have a
» I will read up on the other stuff. Still not sure how to derive the CI. ...
Eventually the book
may help.
Especially chapter 10 Equivalence assessment for clinical endpoints.
If you don't own this book, gimme a hint.
» For such cases we are setting
logscale
to False, right?Correct in so far if we use the approximation that the estimate of µR is (statistically) greater than zero. A very reasonable assumption for the usual metrics AUC and Cmax IMHO.
But this has than nothing to do with Fieller’s (‘fiducial’) confidence interval, a more correct method for deriving a confidence interval for the ratio of untransformed PK metrics.
PowerTOST has for this case the functions
- CI.RatioF()
- power.RatioF()
- sampleN.RatioF()
Have a look into the man pages of these functions and notice that these functions don't have a
logscale
argument.» I will read up on the other stuff. Still not sure how to derive the CI. ...
Eventually the book
Hauschke D, Steinijans VW, Pigeot I.
Bioequivalence Studies in Drug Development
Chichester: John Wiley; 2007
may help.
Especially chapter 10 Equivalence assessment for clinical endpoints.
If you don't own this book, gimme a hint.
—
Regards,
Detlew
Regards,
Detlew
Complete thread:
- On CI calculation, untransformed metrics ElMaestro 2019-11-29 03:40 [General Statistics]
- Fieller’s (‘fiducial’) confidence interval Helmut 2019-11-29 10:03
- Fieller’s (‘fiducial’) confidence interval ElMaestro 2019-11-29 15:53
- Fieller’s (‘fiducial’) confidence intervald_labes 2019-11-29 17:20
- Fieller’s (‘fiducial’) confidence interval ElMaestro 2019-11-30 05:11
- power.TOST with logscale=FALSE d_labes 2019-11-30 14:01
- Fieller’s (‘fiducial’) confidence interval ElMaestro 2019-11-30 05:11
- Fieller’s (‘fiducial’) confidence intervald_labes 2019-11-29 17:20
- Fieller’s (‘fiducial’) confidence interval ElMaestro 2019-11-29 15:53
- On CI calculation, untransformed metrics PharmCat 2019-11-29 12:05
- Fieller’s (‘fiducial’) confidence interval Helmut 2019-11-29 10:03