title: If the ratio of hazards r(t)=λe(t)/λc(t) does not depend on time t then the proportional hazards assumption holds.
authors.affiliation: Genentech, South San Francisco, California.
authors.forename: Larry Frank
authors.initials: LF
authors.lastname: Leon
authors.forename: Bann-Mo
authors.initials: BM
authors.lastname: Day
authors.forename: Xiaoping Sylvia
authors.initials: XS
authors.lastname: Hu
mesh_terms: D056808:Biostatistics; D002983:Clinical Competence; D006801:Humans; D016016:Proportional Hazards Models