title: The alpha spending function approach to interim data analyses.
authors.affiliation: Department of Statistics University of Wisconsin-Madison 53706, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: DeMets
authors.forename: G
authors.initials: G
authors.lastname: Lan
mesh_terms: D002986:Clinical Trials as Topic; D003627:Data Interpretation, Statistical; D006801:Humans; D012107:Research Design