February, 2003
© 2000, 2001
Scott S. Emerson, M.D., Ph.D.
Statistical basis for
stopping criteria (cont.)
Stochastic
Curtailment
·High
probability that a particular decision will be made at final analysis
·
·Calculate
probability of exceeding some critical value conditional on data
observed so far
·
·Probability
calculated based on hypothesized treatment effect (which
hypothesis?) or current estimate