Guidelines and caveats for quality of life measurement in clinical practice and research.

"Quality of Life" is rapidly becoming part of the clinical evaluation process, both as a specific outcome measure in formal clinical trials, and as a bedside concept. This paper provides an historical perspective on the development of the paradigm, and outlines its basic properties. Finally, some pragmatic guidelines for the design, conduct and interpretation of quality of life trials are offered in order that a standard for implementation and evaluation may be developed.