Assessing quality of life in patients with epilepsy.

The importance of quality-of-life (QOL) assessments in providing quantified information about the impact of chronic illness and its treatment is now generally accepted. For epilepsy, QOL assessment is a relatively recent development, but it is increasingly included within clinical trial protocols. Clinical trials in epilepsy that have included a comprehensive QOL assessment, although still relatively few in number, have examined the effectiveness both of broad management policies and of individual drug therapies. There are a number of important conceptual, methodological and practical issues behind the measurement of quality of life as an outcome of care in epilepsy that are being addressed through current efforts to develop standardised QOL instruments. In trying to assess quality of life in epilepsy, as in any other condition, it is important to satisfy the universal requirements of a scientific instrument-that it be valid, reliable, sensitive in change and practical. To date, the main 'formal' approaches to QOL assessment in epilepsy have involved the development of a novel QOL measure from first principles, customising of a previously developed generic measure, identification of a battery of generic and disease-specific scales addressing specific QOL domains, and adoption of an individual patient-generated approach. These various efforts have produced a battery of potentially valuable tools and approaches. Although QOL assessment is now mainly on the epilepsy research agenda, some important challenges remain to be met. These include the development of comprehensive, age-related measures for children with epilepsy, further investigation of the psychometric properties of the available measures for adults, issues of cross-cultural application and use with proxy informants, and the development of utility-based measures.