The quality of life: design and evaluation of a self-assessment instrument for use with cancer patients.

An attempt was made to define the concept of 'quality of life' and outline the development of a self-assessment instrument for detecting the changes in life as a whole which result from the presence and treatment of malignant disease. A comparison was made between three different scoring systems, familiar in psychometric assessment, although less familiar in nursing. The items selected for inclusion in the measurement instrument were based on an existing symptom distress scale and on the previously identified concerns of cancer patients. The relationship between such symptoms and the activities of daily living was explored. Each item, and the instrument as a whole, appeared to be reliable and to represent a valid means of assessing the impact of the disease on patient well-being. It was simple to use and straightforward to score and appeared accurately to reflect the patients' general condition.