Abstracts

Rationale: Employing a methodology new to epilepsy, the purpose is to understand the relative importance of specific attributes of AED treatments and the tradeoffs that patients make between seizure control and tolerability. Methods: US adult patients with a self-reported physician diagnosis of epilepsy and partial seizure symptoms completed a web-enabled, choice-format conjoint survey. Patients were enrolled based on previous failure of at least 1 AED and currently taking at least 1 AED representing a spectrum of uncontrolled epilepsy. Patients were presented with a series of 9 trade-off questions to evaluate attributes of hypothetical add-on AEDs. AED attributes were selected based on a literature review of controlled clinical trials and included seizure reduction (100%, 75%, 50%, 25%), short-term side effects (dizziness, feeling sleepy, headache, nausea, tremor, double or blurred vision, and skin rash), long-term side effects and their impact on activities of daily living (confusion, memory problems, feeling tired, or mood changes), difficulty urinating, weight change (gain, loss, or no change), dosing frequency, and personal medicine cost. Data were weighted to represent US population with epilepsy and estimated using a combined ranked-logit/conditional-logit model. Data were controlled for baseline seizure frequency. Results: 209 subjects were analyzed, with a mean age of 44 years; 53% female, 91% white, 70% with some college education, and 29% with disability. Subjects were taking on average 2 AEDs and previously tried an average of 4 AEDs; and reported having an average of 4 seizures in the past 3 months. Based on the trade-off tasks, subjects ranked seizure reduction the most important AED attribute (importance rating=10.0). Remaining attributes ranked in decreasing order of importance were: long-term confusion or memory problems (7.5), short-term side effects (5.1), long-term fatigue or mood changes (3.9), difficulty urinating (2.4), and weight change (2.4). Dosing frequency had no effect. Seizure freedom was 2.5 times more important than long-term fatigue or mood changes, and 4 times more important than a 15-pound weight gain. Long-term confusion or memory problems were 3 times more important than a 15-pound weight gain, and about 2 times more important than long-term fatigue or mood changes. Seizure freedom was 1.6 times more important than a 50% reduction in seizures. Holding everything else constant, patients, on average, valued seizure freedom at $224 (95% CI: $146-$338) a month while the value of a 50% reduction in seizures was $137 ($81-$212). Conclusions: After controlling for baseline differences in seizure frequency, patients with uncontrolled epilepsy consider seizure reduction the most important attribute, and for which, patients are willing to accept short and long-term side effects.