>Jannik Helweg-Larsen wrote:
>Dear list
>
>Using Stata 8.1
>
>I'm unsure on how to calculate the required sample for the following trial,
>been searching by findit for equivalence ado's without finding my answer:
>
>We are planning to do a 2 year equivalence trial.The current standard of
>treatment has a 2 year failure rate of 7%: In our trial of a new drug, the
>treatments will be considered equivalent if the 95% confidence interval are
>within the bound of -12% to 12%, which we believe is the the largest
>difference that would be considered clinically acceptable.
>any suggestions?
As has been pointed out, an absolute difference in risk of +/- 12% would
swamp the
