Bioequivalence and Bioavailability Forum

To Err is Human [General Statistics]

posted by d_labes – Berlin, Germany, 2010-07-16 12:42 (5814 d 19:56 ago) – Posting: # 5644
Views: 16,458

"If debugging is the process of removing bugs,
then programming must be the process of putting them in."
(Edsger W. Dijkstra)

Dear Paolo,

❝ »... You must calculate T-0.5(R1+R2).

❝ My bad on this. I went through my code a number of times but didn't even notice this!!! :-(

See the subject of these posts and the slogan of he day :-D

.
Or another one in German "Man sieht den Wald vor lauter Bäumen nicht!" (Rough translation: Don't see the wood for the trees.)

❝ I revised this two as well (see way below for my codes :-D ). After revising, I ran my models however I got a different result than the one gotten by d_labes (see below). Mine is 0.023485.

I have calculated using (is theta in your code)
theta² = ((log(1.25)/0.2936)²=(0.76)²
(BTW: Yes nitpickers, of course I know it's really (log(1.25)/sqrt(log(0.3*0.3+1)))^2=(0.7601283...)^2 :cool:

.)

This is recommended by Tothfalusi et. al. (see here for literature) to avoid a discontinuity at the switching variance of CV=30% (switch from usual 80 ... 125% acceptance range to the widened ranges) and is the regulatory constant in the new EMA bioequivalence guidance.
This discontinuity leads to a high alpha-inflation around CV=30%.

❝ I am also confused with the difference between the S2wr results by the ABE SAS code by FDA (page 9 of progesterone guideline) using PROC Mixed and the S2wr formula for intra-subject contrasts. I tried using both as well. I produced the results that was earlier posted. Why is it that Sigma2WR values are different? Is this ok?

(color by me)

Dear Paolo: Sorry but this question is plaguing us as well and is source of our continuing discussion here.
Especially we don't know if one can trust in the results of the FDA Proc Mixed code in case of the extra-reference design your data came from. :ponder:

—
Regards,

Detlew

Complete thread:

SABE Reference Variability and CI Computation preyes323 2010-07-12 17:12 [General Statistics]
- Dataset Helmut 2010-07-12 17:26
  - Dataset preyes323 2010-07-12 18:20
    - Data format Helmut 2010-07-12 18:38
      - Data format preyes323 2010-07-13 01:16
        
        SAS and/or Phoenix/WinNonlin-experts around? Helmut 2010-07-13 02:29
        
        Phoenix/WinNonlin-experts around? d_labes 2010-07-13 12:15
        
        Phoenix/WinNonlin-experts around? Helmut 2010-07-13 13:42
        
        Mixed interest d_labes 2010-07-13 15:11
        
        Mixed interest Helmut 2010-07-13 19:19
        
        lme() answer and beyond ... d_labes 2010-07-14 10:41
        
        lme() answer and beyond ... Helmut 2010-07-14 13:47
        
        AIC, BIC and that all ... d_labes 2010-07-15 12:01
        
        To Err is Human d_labes 2010-07-13 11:51
        
        To Err is Human, but... Helmut 2010-07-13 13:45
        
        ... to Arr is Pirate d_labes 2010-07-13 15:47
        
        Brilliant page!!! ElMaestro 2010-07-14 21:03
        
        To Err is Human preyes323 2010-07-14 14:45
        
        Heads up! Helmut 2010-07-14 15:17
        To Err is Teacher d_labes 2010-07-15 11:05
        
        To Err is Human preyes323 2010-07-16 02:28
        
        To Err is Humand_labes 2010-07-16 10:42
        
        To Err is Human preyes323 2010-07-17 11:14
        
        Regulatory constants d_labes 2010-07-19 10:00
        
        Data format ElMaestro 2011-02-06 11:54
        
        SAS System Viewer Helmut 2011-02-06 13:02

To Err is Human [General Sta­tis­tics]

Complete thread:

To Err is Human [General Statistics]