Conceptualization and measurement of quality of life as an outcome variable for health care intervention and research.

If health care providers are to be able to document effective outcomes resulting from their interventions, they must first develop clear conceptual definitions for the outcomes, and then select measures that represent these concepts. No consensus exists in the health care disciplines about what quality of life is or how it should be measured. This paper presents historical and conceptual arguments in favour of a particular definition of quality of life, and distinguishes between quality of life and concepts often confused with it in the literature: symptoms, mood, functional status, and general health status. Whether quality of life is actually amenable to change as a result of health care interventions, and whether we ought to be trying to influence clients' quality of life is also discussed. We conclude that quality of life is an important outcome of health care intervention. However, traditional approaches to influencing quality of life may be misdirected, and the relative importance of our interventions to clients--whose opinions matter the most--ought to be put into perspective.