Quality-of-life outcomes of initiating treatment with standard and newer antiepileptic drugs in adults with new-onset epilepsy: findings from the SANAD trial

Abstract

Objective: To compare quality-of-life (QoL) outcomes over 2 years following initiation of treatment with a standard or newer antiepileptic drug (AED) in adults with new-onset epilepsy. To examine the impact of seizure remission and failure of initial treatment on QoL outcomes measured over 2 years.

Methods: We conducted a pragmatic, randomized, unblinded, multicenter, parallel-group clinical trial (the Standard and New Antiepileptic Drugs [SANAD] trial) comparing clinical and cost effectiveness of initiating treatment with carbamazepine versus lamotrigine, gabapentin, oxcarbazepine and topiramate, and valproate versus lamotrigine and topiramate. QoL data were collected by mail at baseline, 3 months, and at 1 and 2 years using validated measures. These data were analyzed using longitudinal data models. Continuous QoL measures, time to 12-month remission and time to treatment withdrawal were explored using joint models.

Results: Baseline questionnaires were returned by 1,575 adults; 1,439 returned the 3-month questionnaire, 1,274 returned the 1-year questionnaire, and 1,121 returned the 2-year questionnaire. There were few statistically significant differences between drugs over 2 years in QoL outcomes. Significant association was identified between QoL scores over the 2-year time frame and the risk of experiencing a 12-month remission or treatment withdrawal over that period.

Significance: The choice of initial treatment had no significant effect on QoL by 2-year follow-up. However, overall QoL was reduced with continued seizures, adverse events, and failure of the initial treatment.

Keywords: Antiepileptic drugs; Joint models; Outcomes research; Seizure remission; Treatment failure.