This page is a modified version of a page made by:
David A. Schoenfeld, Ph.D.
*Accrual time: The time it takes to enroll all patients, when the follow-up time is fixed this can be set to 0. It needs to be specified when all participants are followed until the study stops, i.e. the accrural interval adds observation time.
This method does not take attrition into consideration.
The program "Power and Precision" can handle drop-outs and can be purchased from www.powerandprecision.com