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Quality of Life

  1. Diane L. Fairclough1,
  2. Patricia A. Ganz2

Published Online: 15 JUL 2005

DOI: 10.1002/0470011815.b2a01048

Encyclopedia of Biostatistics

Encyclopedia of Biostatistics

How to Cite

Fairclough, D. L. and Ganz, P. A. 2005. Quality of Life. Encyclopedia of Biostatistics. 6.

Author Information

  1. 1

    University of Colorado Health Sciences Center, Denver, CO, USA

  2. 2

    UCLA Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA

Publication History

  1. Published Online: 15 JUL 2005


In the health sciences, assessment of quality of life and other patient-reported outcomes are now an integral component of patient-focused research. Health-related quality of life (HRQoL) is a multidimensional construct that assesses the extent to which one's usual or expected physical, emotional, and social well-being are impacted by a medical condition or its treatment. HRQoL may be assessed using generic or disease-specific instruments. These instruments consist of a set of questions, method of administration, instructions for administration, method of scoring and analysis, and interpretation. Validation of these instruments includes assessment of content validity, internal consistency, test–retest reliability, and discriminant and predictive validity. Some of the statistical issues that arise in the analysis of studies with HRQoL assessments are multiple endpoints, missing data (informative dropout), and interpretation (statistical versus clinical significance).


  • quality of life;
  • health status;
  • patient-reported outcomes