February, 2003
© 2000, 2001  Scott S. Emerson, M.D., Ph.D.
Session 2: 19
Inadequacy of Fixed Sample Methods
Sequential monitoring of a trial
Data are analyzed after accrual of each observation
·
·(Group sequential monitoring: analysis after groups of observations accrued)
·
·Analyses must take into account the repeated analyses of the same data
-Sampling distribution of the test statistic is altered
-Frequentist properties are altered