Improving health-related quality of life (HRQOL) has become recognized as an essential component of treating patients with epilepsy. In recent years, several rating scales have been developed that focus on both common adverse effects and various aspects of HRQOL that are more relevant to this patient population. Increasingly, such assessments are being incorporated into clinical trials, as it becomes clear that improvements in overall quality of life are an important feature of drug therapy. Here we present the design of a large, community-based trial evaluating the effects of switching from immediate-release carbamazepine to twice-daily, beaded, extended-release carbamazepine (Carbatrol). As this trial involves switching formulations of the same compound, we expect to find only small differences in efficacy but significant differences in tolerability and quality-of-life measures. To identify appropriate instruments that could measure these factors, here we review several epilepsy-specific scales used to monitor adverse events and HRQOL and discuss their potential utility in the context of the proposed trial. (C) 2004 Elsevier Inc. All rights reserved.