Abstract:
In a sequential clinical trial, accrual of data on patients often continues after the stopping
criterion for the study has been met. This is termed “overrunning.”Ov errunning occurs mainly when the
primary response from each patient is measured after some extended observation period. The objective of
this article is to compare two methods of allowing for overrunning. In particular, simulation studies are
reported that assess the two procedures in terms of how well they maintain the intended type I error rate.
The effect on power resulting from the incorporation of “overrunning data”using the two procedures is
evaluated
