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Survival Distributions and Their Characteristics

  1. John P. Klein

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a11074

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Klein, J. P. 2005. Survival Distributions and Their Characteristics. Encyclopedia of Biostatistics. 8.

Author Information

  1. Medical College of Wisconsin, Milwaukee, WI, USA

Publication History

  1. Published Online: 15 JUL 2005


The four basic functions that characterize the probability distribution of the time to an event are presented. These functions, the survival function, the density or mass function, the hazard rate, and the mean residual life function are presented, and the relationship between the functions is discussed. Classes of distributions that reflect aging properties are presented. These classes include the increasing hazard rate (IHR) class, the increasing hazard rate on the average class (IHRA), the decreasing mean residual life (DMRL) class, the new better than used (NBU) class, the new better than used in expectation class (NBUE) and the harmonic new better than used in expectation class (HNBUE).


  • survival function;
  • hazard function;
  • mean residual life;
  • median residual life;
  • aging classes