Quality of life as an outcome measure for epilepsy clinical trials.

Assessment of health-related quality of life (HRQOL) has been developed to the point where well-validated instruments are being used in clinical trials. Data on the impact of new treatments can be used for formulary and regulatory decisions if the clinical trials are designed with appropriate instruments and sample sizes. However, more information is needed about the clinical significance of small differences in total or scale scores. Similarly, pharmacoeconomic studies should be prospective assessments that include evaluation of HRQOL as well as cost. In the future, these new aspects of outcome assessment are expected to be used as an adjunct to traditional seizure frequency and adverse effect reports in the selection of antiepileptic drugs.