Sample size estimation for parallel design [Power / Sample Size]

posted by Nav Coelho – 2007-07-20 18:14 (6118 d 08:30 ago) – Posting: # 916
Views: 26,007

Dear all,

I have data from a parallel pilot study and am using that to estimate the sample size for a pivotal study. The formula that I am using requires an estimate of the inter subject variability which I don't have. I have the total variability (sqrt(MSE)). Is there a way to estimate intersubject variability from a parallel design or would it be correct to use the total variability instead?

Would it be correct to estimate inter-subject var as sd/mean for test and reference separately and then take the average?

And one last question, how correct is it to take 60% of inter subject (calculated as sd/mean) to be the intrasubject variability?

Thanks in Advance!
Nav Coelho

Complete thread:

UA Flag
Activity
 Admin contact
22,988 posts in 4,825 threads, 1,656 registered users;
93 visitors (0 registered, 93 guests [including 1 identified bots]).
Forum time: 02:44 CEST (Europe/Vienna)

The whole purpose of education is
to turn mirrors into windows.    Sydney J. Harris

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