Design, Monitoring, and Analysis of Clinical Trials

February, 2003

Session 3: 49

Measuring Study Time

Possible approaches

At each analysis estimate the statistical information available, and use that estimate at all future analyses

·Theoretically, this can result in estimates of negative information gained between analyses

At each analysis use the sample size with the current best estimate of V

·The 1:1 correspondence between boundary scales is thus broken at previously conducted analyses