title: Calculating the number needed to treat for trials where the outcome is time to an event.
authors.affiliation: Imperial Cancer Research Group Medical Statistics Group, Centre for Statistics in Medicine, Institute of Health Sciences, Headington, Oxford OX3 7LF. d.altman@icrf.icnet.uk
authors.forename: D G
authors.initials: DG
authors.lastname: Altman
authors.forename: P K
authors.initials: PK
authors.lastname: Andersen
mesh_terms: D002986:Clinical Trials as Topic; D003625:Data Collection; D011379:Prognosis; D016016:Proportional Hazards Models; D018401:Sample Size; D016019:Survival Analysis