title: A simple algorithm for designing group sequential clinical trials.
abstract: This article describes a simple algorithm for calculating probabilities associated with group sequential trials. This allows the choice of boundaries that may not be among those implemented in available software.
authors.affiliation: Massachusetts General Hospital-Biostatistics, Boston 02114, USA. dschoenfeld@partners.org
authors.forename: D A
authors.initials: DA
authors.lastname: Schoenfeld
mesh_terms: D000465:Algorithms; D001699:Biometry; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D006801:Humans; D007654:Ketoconazole / Q000627:therapeutic use; D018447:Medical Futility; D011336:Probability; D012128:Respiratory Distress Syndrome / Q000188:drug therapy; D012984:Software; D017211:Treatment Failure
chemical_list: D007654:Ketoconazole