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Age–Period–Cohort Analysis

  1. Theodore R. Holford

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a03003

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Holford, T. R. 2005. Age–Period–Cohort Analysis. Encyclopedia of Biostatistics. 1.

Author Information

  1. Yale University School of Medicine, New Haven, CT, USA

Publication History

  1. Published Online: 15 JUL 2005


Age–period–cohort analysis refers to the interpretation of temporal trends in disease incidence or mortality rates in terms of the three time scales, age, calendar date (period), and year of birth (cohort). We present graphical and analytic methods for understanding trends in disease rates. A fundamental issue of identifiability arises in some models because of a linear constraint on these time scales: year of birth plus age equals the current calendar year. We review parametric and nonparametric approaches to estimate identifiable aspects of the data, such as the curvature of temporal trends.


  • disease incidence trends;
  • descriptive epidemiology;
  • identifiability;
  • estimable functions;
  • curvature