February, 2003
© 2000, 2001  Scott S. Emerson, M.D., Ph.D.
Session 2: 145
Evaluation of Designs
Decision boundary at each analysis
Value of test statistic leading to rejection of null
·Variety of boundary scales possible
Often has meaning for applied researchers (especially on scale of estimated treatment effect)
·Estimated treatment effects may be viewed as unacceptable for ethical reasons based on prior notions
·Estimated treatment effect may be of  little interest due to lack of clinical importance or futility of marketing