Karmegams
☆    

India,
2011-06-16 06:53
(5482 d 05:51 ago)

Posting: # 7132
Views: 6,325
 

 CV from pilot study or reported literature [Power / Sample Size]

Dear Sir,

The intra-subject CV from pilot study or reported literature is used in sample size calculation for bioequivalence study.

The intra-subject CV is due to drug and formulation. So, is it appropriate to use CV-intra from literature of other’s product (others’ formulation) for sample size calculation?


Regards
Skar
Helmut
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Homepage
Vienna, Austria,
2011-06-16 15:12
(5481 d 21:32 ago)

@ Karmegams
Posting: # 7139
Views: 5,283
 

 Credibility of data

Dear Skar!

❝ Dear Sir,

    Not interested in ladies’ opinions


❝ The intra-subject CV is due to drug and formulation.


Not quite. You should also consider
  • design issues (number and location of sampling time points, single dose vs. steady state),
  • clinical setting (food, posture, physical activity), and
  • analytical variability (mainly stability and to a lesser degree the method itself).

❝ So, is it appropriate to use CV-intra from literature of other’s product (others’ formulation) for sample size calculation?


Yes, but try to judge the credibility of the study. Add a safety margin. Using the plain number ‘as is’ I would consider careless.

Don’t forget your previous thread and today’s quote:

Statistics are no substitute for judgment. Henry Clay


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Karmegams
☆    

India,
2011-06-17 13:57
(5480 d 22:47 ago)

@ Helmut
Posting: # 7148
Views: 5,225
 

 Credibility of data

Dear HS,

Thank you very much for your explaination.

❝ ❝ The intra-subject CV is due to drug and formulation.


❝ Not quite. You should also consider

  • design issues (number and location of sampling time points, single dose vs. steady state),
  • clinical setting (food, posture, physical activity), and
  • analytical variability (mainly stability and to a lesser degree the method itself).

If the study is well designed and conducted in standardised and controlled manner, i believe that the variability due to design issues, clinical setting and analytical method is very less or negligible.

Regards,
Skar
GSTATS
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Homepage
India,
2011-06-16 22:02
(5481 d 14:42 ago)

@ Karmegams
Posting: # 7142
Views: 5,273
 

 CV from pilot study or reported literature

Dear Skar,

❝ The intra-subject CV from pilot study or reported literature is used in sample size calculation for bioequivalence study.


I would suggest to go with CV from pilot study, done in-house, if it is there. So that one could have a variability from population in which pivotal study is planned. If not, then no other option but to search literature for CV.

Regards,
GSTATS

Let Noble Thoughts come from Every Side: RIG VEDA
rajneesh singh
☆    

2011-06-17 12:14
(5481 d 00:30 ago)

@ GSTATS
Posting: # 7147
Views: 5,278
 

 CV from pilot study or reported literature

Dear Skar,

Justification for sample size should be appropriate regrading Design & Formulation. we can use suitable literature otherwise it is not available then we go for pilot study.


Regards,

RS


Edit: Full quote removed. Please delete anything from the text of the original poster which is not necessary in understanding your answer; see also this post! [Ohlbe]
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