The assessment of values in laryngeal cancer: reliability of measurement methods.

Although quantitative estimates of patients' attitudes toward the relative importance of different aspects of health are of great potential usefulness in medical decision making, there is little information about the stability of such values over time, particularly in patients whose clinical state is changing. To examine these questions, we selected a group of patients with laryngeal cancer undergoing treatment with radiotherapy. In this group of patients clinical problems are relatively circumscribed and related to the voice, and a temporary deterioration in voice-related symptoms and abilities is expected during treatment. Thirty patients were interviewed at the start and completion of a month's course of treatment. At each interview patients rated the quality of their own voices using a number of visual analogue scales and also provided both holistic and decomposed quantitative values for the importance of different aspects of voice function and sound. Although the analogue scales demonstrated the anticipated deterioration in the quality of the patients' voices, these changes in clinical state were not accompanied by any changes in the values the patients assigned to each aspect of voice sound and function. These results indicate that at least in the short term the values expressed by patients appear to be stable and uninfluenced by changes in their own clinical state. Longer term studies involving more systemic illnesses should now be carried out.