Pain and quality of life.

This paper deals with the impact of pain on quality of life (QOL). Two major factors have contributed to the enhanced importance of QOL in recent years: the increasing frequency of pain and the resources devoted to its treatment, and the growing theoretical insight that pain affects the person as a whole. QOL is defined as the person's evaluation of his or her well-being and functioning in different life domains. It is a subjective, phenomenological, multidimensional, dynamic, evaluative, and yet quantifiable, construct. Commonly used scales for its assessment (eg, WHOQOL, SF-36) are described. Studies show that pain affects most domains of QOL, primarily physical and emotional functioning. The effect depends on the extent, duration, acuteness, intensity, affectivity, and meaning of the pain as well as on the underlying disease and the individual's characteristics. QOL is sensitive also to the treatment of pain and treatment modalities, as shown particularly by studies on cancer pain. Pain reduction is not always attended by the expected improvement in QOL. Pain is not synonymous with poor QOL and constitutes only one important factor determining QOL. The main conclusions are that treatment of pain should be multidisciplinary, considering the impact of pain and the treatment on QOL and targetting also improvement of the affected domains of QOL.