Impact of seizure frequency reduction on health-related quality of life among clinical trial subjects with refractory partial-onset seizures: A pooled analysis of phase III clinical trials of eslicarbazepine acetate

•Clinically meaningful improvements in health-related quality of life were observed with a ≥ 50% seizure frequency reduction.•Further improvement in health-related quality of life was observed with greater reductions in seizure frequency.•The efficacy of adjunctive eslicarbazepine acetate was associated with a positive impact on health-related quality of life.

BackgroundSubjects who received eslicarbazepine acetate (ESL) as adjunctive therapy experienced significantly greater seizure frequency reduction (SFR) than placebo in three phase III, randomized, double-blind trials. This analysis compared changes in health-related quality of life (HRQOL) between treatment responders and non-responders across the pooled, per-protocol population (N = 842) using the validated Quality of Life in Epilepsy Inventory-31 (QOLIE-31).MethodsQOLIE-31 scores were calculated for Total Score (TS) and seven subscales; higher scores indicate better HRQOL. Mean changes from baseline were calculated. Analysis of covariance examined least square mean (LSM) differences in final scores between responders (≥ 50% and ≥ 75% SFR) and non-responders. Clinical significance was based on established minimal clinically important differences (MCIDs).ResultsMean changes were greater among responders for TS (5.2 versus 1.4 for ≥ 50% SFR; 7.5 versus 1.9 for ≥ 75% SFR) and all subscales. Additionally, the percentage of subjects with changes meeting or exceeding MCIDs was higher among responders for TS (48.4% versus 33.9% for ≥ 50% SFR; 56.9% versus 35.8% for ≥ 75% SFR) and all subscales. Responders had significantly higher final scores for TS (LSM difference = 4.0 for ≥ 50% SFR; LSM difference = 5.7 for ≥ 75% SFR) and all subscales except emotional well-being at ≥ 50% SFR. LSM differences exceeded MCIDs at ≥ 75% SFR for TS and five of seven subscales, and two subscales at ≥ 50% SFR. In a subgroup analysis with placebo removed, LSM differences were larger overall.SignificanceIn clinical trials of adjunctive ESL, higher levels of SFR were associated with greater improvements in HRQOL.