February, 2003
© 2000, 2001, 2003 Scott S. Emerson, M.D., Ph.D.
Frequentist Methods 1: 28
Example
Two-sided level .05 test of a normal mean (1 sample)
Fixed sample design
·Null: Mean = 0; Alt  : Mean = 2
·Maximal sample size: 100 subjects
Early stopping for harm, equivalence, efficacy according to value of sample mean
(Example stopping rule taken from a two-sided symmetric design (Pampallona & Tsiatis, 1994) with a maximum of four analyses and O’Brien-Fleming (1979) boundary relationships)