Quality of life as an outcome measure in nursing research. "May you have a long and healthy life".

Quality of life has emerged as an important concept and outcome in health and health care. Policy-makers, researchers, clinicians, and the public at large consider perceived quality of life to be an important dimension of the health of a population or an individual. The nature of nursing is such that many of its anticipated outcomes relate to improvement in the quality of life of individuals and populations. There continues to be debate about the actual definition of quality of life, and a concept that is difficult to define will naturally pose challenges to measurement. This has not impeded the proliferation of quality-of-life instruments, since the concept is recognized as an increasingly important clinical and research outcome. Progress has been made in clarifying and operationalizing the concept. We propose a conceptual viewpoint that separates what quality of life is from what contributes to quality of life. This will assist nurse researchers planning to use quality of life as an outcome in evaluating nursing interventions. In clinical or research situations, for the purposes of measurement, an operational definition of quality of life stems from a definition of health. From this is drawn a definition of health-related quality of life (HRQL). For the purpose of outcome measurement, the operational definition relates to the domains important to the study population and the particular health intervention under study. Issues that arise in the measurement of HRQL are also presented.