Anu
★    

India,
2013-08-26 09:15
(4318 d 05:02 ago)

Posting: # 11341
Views: 8,105
 

 Confidence limits [General Sta­tis­tics]

Hi all,

Greetings!

Kindly help me in knowing how can we change the values lying between confidence Interval of (-20% to 20%) e.g (90% lower limit (-1.07) & 90% upper limit (-0.30)) into the values lying between the CI (80-125)%.

Thanks & Regards
Anu
Dr_Dan
★★  

Germany,
2013-08-26 13:05
(4318 d 01:11 ago)

@ Anu
Posting: # 11343
Views: 6,774
 

 Confidence limits

Dear Anu
Could you please repeat your question in other words? I do not get the sense.
Kind regards
Dan

Kind regards and have a nice day
Dr_Dan
Anu
★    

India,
2013-08-27 08:26
(4317 d 05:50 ago)

@ Dr_Dan
Posting: # 11352
Views: 6,704
 

 Confidence limits

Hi Dr_ Dan,

❝ Could you please repeat your question in other words? I do not get the sense.


Sorry if the language was not clear.
I just need to know in FDA the accepted confidence intervals ranges are (80%-125%) & (-20% to +20%).
I have a data for a reference product whose 90% CI is (-1.07% to -0.30%) on the CI scale of (-20% to +20%).
I want to transform it into the CI scale of (80%-125%).
Can I do this?


Thanks & Regards
Anu
Helmut
★★★
avatar
Homepage
Vienna, Austria,
2013-08-27 17:07
(4316 d 21:10 ago)

@ Anu
Posting: # 11357
Views: 6,624
 

 Still unclear…

Hi Anu,

❝ I just need to know in FDA the accepted confidence intervals ranges are (80%-125%) & (-20% to +20%).


The acceptance range is 80.00–125.00% (90% CI in percent rounded to two decimals).

❝ I have a data for a reference product whose 90% CI is (-1.07% to -0.30%) on the CI scale of (-20% to +20%).


This doesn’t makes sense to me. Do you mean data for a test product (in % of the reference)?

❝ I want to transform it into the CI scale of (80%-125%).

❝ Can I do this?


Duno. I don’t believe in these numbers – where do they come from? In % of the reference the CI would be 98.93–99.70%. Assuming a 2×2 cross-over that would translate even for the smallest acceptable sample size of 12 into a CV of 0.52% [sic]. Simply impossible.

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz
[image]

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes
Anu
★    

India,
2013-08-28 11:08
(4316 d 03:08 ago)

@ Helmut
Posting: # 11365
Views: 6,542
 

 Is it still unclear :( ?

Hi Helmut,

❝ This doesn’t makes sense to me. Do you mean data for a test product (in % of the reference)?


Actually the 90% CI is for the test-reference

❝ Duno. I don’t believe in these numbers – where do they come from?


I don't have any raw data, just got this confidence interval (on -20% to +20%) scale from my boss. And its a two way cross over study with 21 subjects. On the basis of which my objective is to calculate the sample size. Which I will be doing with R software and the FARTSSIE Excel sheet. So, it came in my mind why not to transform this CI into (80.00 to 125.00)%. It should be possible? Does there exist any such transformation relation between these two different CI scales i.e (80.00 to 125.00)% and (-20.00 to +20.00)?

Thanks & Regards
Anu
jag009
★★★

NJ,
2013-08-26 17:48
(4317 d 20:29 ago)

@ Anu
Posting: # 11348
Views: 6,671
 

 Confidence limits

Hi,

??? You mean from PK data or just the confidence interval values?

John
Anu
★    

India,
2013-08-27 08:28
(4317 d 05:48 ago)

@ jag009
Posting: # 11353
Views: 6,631
 

 Confidence limits

Hi John,

Need to transform just the confidence interval values.

Thanks & Regards
Anu
ElMaestro
★★★

Denmark,
2013-08-27 08:47
(4317 d 05:29 ago)

@ Anu
Posting: # 11354
Views: 6,751
 

 Confidence limits

Hi Anu,

❝ Need to transform just the confidence interval values.


If you have CI results on the log-scale then you just need to exponentiate them. Which is what your protocol also says, right?

Judging the numbers you have it does, however, sound like something went seriously pear-shaped with the BE study, the formulation or the data evaluation. Please paste the raw untransformed data and let's have a look.

Pass or fail!
ElMaestro
Anu
★    

India,
2013-08-28 11:12
(4316 d 03:05 ago)

@ ElMaestro
Posting: # 11366
Views: 6,629
 

 Confidence limits

Hi Elmaestro,

❝ If you have CI results on the log-scale then you just need to exponentiate them. Which is what your protocol also says, right?


Right.

❝ Judging the numbers you have it does, however, sound like something went seriously pear-shaped with the BE study, the formulation or the data evaluation. Please paste the raw untransformed data and let's have a look.


Right now I don't have the raw data, will definitely upload once I'll have it.

Thanks & Regards
Anu
UA Flag
Activity
 Admin contact
23,424 posts in 4,927 threads, 1,673 registered users;
50 visitors (0 registered, 50 guests [including 7 identified bots]).
Forum time: 14:17 CEST (Europe/Vienna)

Medical researches can be divided into two sorts:
those who think that meta is better and those
who believe that pooling is fooling.    Stephen Senn

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5