title: Sample size calculation for complex clinical trials with survival endpoints.
abstract: Sample size estimation is important in planning clinical trials. The purpose of this paper is to describe features and use of SIZE, a comprehensive computer program for calculating sample size, power, and duration of study in clinical trials with time-dependent rates of event, crossover, and loss to follow-up. SIZE covers a wide range of complexities commonly occurring in clinical trials, such as nonproportional hazards, lag in treatment effect, and uncertainties in treatment benefit. The use of SIZE is illustrated by several hypothetical examples as well as applications to real study designs, each featuring a statistical issue.
authors.affiliation: Office of Biostatistics Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892- 7938, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Shih
mesh_terms: D000465:Algorithms; D002986:Clinical Trials as Topic; D018592:Cross-Over Studies; D005500:Follow-Up Studies; D008390:Markov Chains; D018401:Sample Size; D012984:Software; D012985:Software Design; D015996:Survival Rate; D013997:Time Factors