February, 2003
© 2000, 2001, 2003 Scott S. Emerson, M.D., Ph.D.
Session 1- Fixed Sample Design: 111
Case Study: Statistical Design Issues
Determining the sample size
Choose sample size to provide desired operating characteristics
·Type I error: .025 when no difference in mortality
·Power: .80 when 5% absolute difference in mortality
·Statistical variablity based on mortality rate of 30% on placebo arm