February, 2003
© 2000, 2001  Scott S. Emerson, M.D., Ph.D.
Session 2: 142
Evaluation of Designs
Sample size requirements
Number of subjects needed is a random variable
Quantify summary measures of sample size distribution
·maximum (feasibility of accrual)
·mean (Average Sample N- ASN)
·median, quartiles
(Particularly consider tradeoffs between power and sample size distribution)