Epilepsy core outcome set for effectiveness trials (EPSET): A systematic review of outcomes measured in registered phase III and IV clinical trials for adults with epilepsy.

At present, little is known about the outcomes measured in studies assessing the effectiveness of treatments for adults with epilepsy. As part of a wider project developing a Core Outcome Set for clinical trials for adults with epilepsy, we summarised the current outcomes and measurement instruments used in completed phase III and IV clinical trials registered in the clinicaltrials.gov and International Standard Randomised Controlled Trial Number (ISRCTN) databases. Of the reviewed studies 104 were deemed eligible. The outcomes that were measured were recorded, and trial registry entries cross referenced against associated peer review publications. In total, 374 unique granular outcome terms were identified, which grouped into 45 outcome concepts across the following domains: seizures, cognitive/behavioural/psychiatric, sleep, general symptom, functional status / disability, emotional functioning, social functioning, delivery of care, life impact, trial processes, side effects / adverse events, pregnancy / offspring, and death. We identified evidence of outcome measurement heterogeneity, with just 10/45 outcome concepts measured in more than half of the identified studies. This association remained when assessing studies grouped by epilepsy chronicity (newly diagnosed vs. chronic/treatment refractory) and epilepsy classification (focal vs. other). These findings highlight the need for a Core Outcome Set for interventional studies for adults with epilepsy to improve consistency of outcome measurement and reporting.