[Health-related quality of life as an outcome measure]

Objective health measures often correlate poorly with the personal burden of illness. Thus, over recent years, there has been a growing interest in health-related quality of life (QOL) as an outcome measure when evaluating treatment effects and health. Self-report instruments are the most commonly used method for measuring QOL, and estimates of reliability and validity assist the selection of appropriate QOL measures. The primary criteria for evaluating QOL instruments are test-retest reliability, internal consistency, content validity, criteria validity, construct validity and responsiveness. Responsiveness refers to an instrument's sensitivity towards changes in health. Knowledge about the methods used when validating QOL instruments may increase confidence in QOL as a relevant outcome measure in medical science. In the clinical setting, using QOL measures may help patients communicate their problems and help doctors and nurses to identify patients' major concerns.