Quality of life in chronic illness.

The concept of health-related quality of life (QOL) is differentiated from generalized QOL. If we are to understand attitudes and behavior of older people regarding the end of life, we need to take account not only of the distress and impairments resulting from poor health, but also of the positive features in the non-health-related areas of their lives that may make them wish to endure the negative aspects of poor health and its treatment side effects. The concept of Valuation of Life is suggested as the mental process that intervenes between negative and positive aspects of daily life on the one hand and older people's wishes for prolonged life and life-extending treatment on the other hand. Research is described which yielded a Valuation of Life Scale. Although many facets of good and poor physical and mental health were related to Valuation of Life, it was primarily positive aspects such as relationships with friends, meaningful time use and positive emotion that were independently associated with Valuation of Life. Valuation of Life was, in turn, the major independent predictor of the number of years people wished to live under a number of conditions of good health, disability, cognitive impairment and pain. It is concluded that both individual treatment decisions and social policy based on QOL associated with health and illness be informed by knowledge that positive aspects of life other than in the health sector are important considerations.