Quality of life: Is the measurable driving out the important?

Quality of life measures are now well established as secondary endpoints in oncology and the clinician/researcher has many reliable measures from which to choose. The increasing importance of patient reported outcomes such as quality of life reflects a shift from a mechanistic biomedical model of disease to a bio-psycho-social model in which the patient is seen, less as an object requiring intervention, and more as a partner in an ongoing negotiated process of treatment in which a broader range of outcomes is considered to be important. The past 20 years have yielded significant advances in the measurement of what is called "health-related quality of life" but there has been little theoretical development of the construct. this paper examines current approaches to the measurement of quality of life and questions some of the important assumptions inherent in them. It is argued than human beings possess highly sophisticated cognitive and perceptual processes that have evolved to generate meaning in a complex world. This struggle for meaning, while common to all mankind, is also inherently individual and it assumes particular importance when quality of life is threatened by disease. The challenge is to develop a theoretical framework and associated measures that more adequately capture this complexity.