|From||Ronán Conroy <email@example.com>|
|Subject||Re: st: Sample size calculation|
|Date||Thu, 27 Oct 2005 12:17:27 +0100|
Thanks. We plan to do the experiment in humans and they will be treatedNo, no. Sample size calculations are done on the difference between the two groups expressed in standard deviations. The actual size of the SD is irrelevant.
with Rebif. The expected size of difference is 2 SD (to be clinically
significant) but my understanding is that to be able to calculate the
sample size (alpha = 0.05, beta = 0.20), we have to know estimated mean
and SD? Is this not true?