Quality-of-life measurements: origin and pathogenesis.

Despite extensive growth in recent years, the field of "quality-of-life" appraisal still evokes debate about basic perception of the concept and is accompanied by a plethora of indexes for measurement. One prime reason for the problems is that the measurements have been transferred from two separate sources - medical health status indexes and social-science population indexes - neither of which was designed for appraising the particular personal distinctions of the way people feel about their own quality of life. When regulatory and commercial incentives were offered for measuring patients' quality of life, it became appraised with the indexes available from the medical and psychosocial sources, even though neither set of indexes was specifically intended for that purpose. They are not developed from the basic principle that a person's "quality of life" is a state of mind, not a state of health, which is uniquely perceived by that person, and which will not be appropriately appraised unless the most cogent personal components are allowed suitable expressions. An approach that lets patients state their own opinions directly can offer the "face validity" or "common sense" that now seems absent from the generally applied measurements.