title: Sample sizes for time-to-event endpoints: should you insure against chance variations in accrual?
abstract: This note addresses the questions of whether one should safeguard against a potential loss of power due to random variations of the accrual time, how this "insurance" can be formulated, and how much the sample size needs to be increased to obtain it.
authors.affiliation: National Center for Tumor Diseases Heidelberg, Germany.
authors.forename: Ulrich R
authors.initials: UR
authors.lastname: Abel
authors.forename: Katrin
authors.initials: K
authors.lastname: Jensen
authors.forename: Irini
authors.initials: I
authors.lastname: Karapanagiotou-Schenkel
mesh_terms: D023381:Endpoint Determination / Q000379:methods*; D006801:Humans; D008962:Models, Theoretical; D011336:Probability; D012107:Research Design; D018401:Sample Size