Health-related quality-of-life issues: optimizing patient outcomes.

Quality of life has emerged as an important health care outcome for patients with chronic illnesses requiring long-term therapy. Disease-specific quality-of-life instruments have been developed as outcome measures for several chronic diseases, and the number of studies that have used quality of life as an outcome measure has increased dramatically in the past 10 years. Quality-of-life measures have not been widely applied in epilepsy, however. Because seizure severity is an important measure of quality of life, seizure severity scales that quantify seizure severity in the evaluation of medical and surgical treatments of epilepsy have been developed for use in clinical trials. The development of a health-related quality-of-life model for epilepsy, including previously validated scales, and its application to the assessment of treatment effects in a clinical trial are described.