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Sample size calculation for randomized selection trials with a time‐to‐event endpoint and a margin of practical equivalence
Author(s) -
Dehbi HakimMoulay,
EmbletonThirsk Andrew,
McCaw Zachary Ryan
Publication year - 2022
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.9490
Subject(s) - sample size determination , equivalence (formal languages) , clinical endpoint , computer science , time point , event (particle physics) , statistics , selection (genetic algorithm) , sample (material) , endpoint determination , clinical trial , mathematics , medicine , artificial intelligence , philosophy , physics , chemistry , discrete mathematics , quantum mechanics , chromatography , aesthetics
Selection trials are used to compare potentially active experimental treatments without a control arm. While sample size calculation methods exist for binary endpoints, no such methods are available for time‐to‐event endpoints, even though these are ubiquitous in clinical trials. Recent selection trials have begun using progression‐free survival as their primary endpoint, but have dichotomized it at a specific time point for sample size calculation and analysis. This changes the clinical question and may reduce power to detect a difference between the arms. In this article, we develop the theory for sample size calculation in selection trials where the time‐to‐event endpoint is assumed to follow an exponential or Weilbull distribution. We provide a free web application for sample size calculation, as well as an R package, that researchers can use in the design of their studies.