Measuring quality of life: apparent benefits, potential concerns.

Quality of life (QOL) research is reviewed in relation to measurement issues and applications to decision-making. Multidimensional standardized questionnaires provide assessments of different aspects of health-related QOL, including psychological, physical and social functioning as well as symptoms. Formal QOL assessments provide systematic, quantitative answers to the kinds of questions clinicians usually ask informally, such as "how have you been lately?" QOL measurements have various uses at different levels of decision-making, from the micro (individual) to the macro (population) level. Examples are applications to clinical trials and to studies of patients' needs for care. Clinical trials have already provided an unexpected result--for patients with advanced disease, pretreatment QOL may predict survival outcome. Such results provide evidence for the validity of QOL measurements, but also raise ethical issues that must be recognized and addressed.