February, 2003
© 2000, 2001, 2003 Scott S. Emerson, M.D., Ph.D.
Session 1- Fixed Sample Design: 109
Case Study: Statistical Design Issues
Defining the statistical hypotheses (cont.)
Alternative hypothesis
·One-sided test for decreased mortality
-Unethical to prove increased mortality relative to comparison group in placebo controlled study
·14 day mortality rate with antibody: 25%
-5% absolute difference in mortality
-(.05 / .30 = 16.67% relative difference)