Abstracts

To investigate healthcare utilization, costs and compare the incidence of adverse events (AEs) in commercially-insured epileptic patients initiating levetiracetam (LEV) or gabapentin (GBP). A retrospective cohort analysis of patients diagnosed with epilepsy was conducted using a large US medical and pharmaceutical claims database (July 2001 - December 2003). Patients without any LEV or GBP prescription during a 6-month baseline period were classified into mutually exclusive treatment groups based on their first LEV or GBP medication prescription. Patients were followed for a total of 12-months with a minimum 3-month duration required. GBP patients were matched on a 1:1 basis to LEV patients by clinical characteristics, seizure and therapy types. Utilization and cost were analyzed using the non-parametric Wilcoxon rank-sum test while risk of AEs was assessed using Cox proportional hazards models. Treatment groups (n=816 each) were comparable: mean age [sim]39 years, [sim]63% women, 64% generalized seizures, 65% adjunctive therapy. Patients received more prescriptions for LEV compared to GBP (mean/patient/year: 8.3 vs 6.0, p[lt]0.001), which generated higher LEV pharmacy costs ($1,319 vs $648, p[lt]0.001). Healthcare utilization was significantly lower in LEV patients than in GBP patients for physician office visits (18.1 vs 20.8, p[lt]0.01), emergency-room visits (8.5 vs 11.0, p[lt]0.01), other outpatient visits (35.7 vs 40.6, p[lt]0.05) and medications other than anti-epileptics (24.4 vs 36.5, p[lt]0.001). Less utilization translated into significantly less cost in favor of LEV for emergency-room visits ($880 vs $1,094, p[lt]0.01) and medications other than anti-epileptics ($1,995 vs $2,396, p[lt]0.001). Although the difference did not reach statistical significance, GBP showed higher costs than LEV for hospitalizations ($11,189 vs $8,275) and overall costs (i.e., total pharmacy, outpatient and inpatient costs: $24,001 vs $22,432). The percentage of patients free of any AE during follow-up was significantly higher for LEV than for GBP (38% vs 29%, p[lt]0.001). Median time to first AE was longer for LEV than for GBP (42 vs 28 days). The hazard ratio for the time to first AE (LEV vs GBP) was 0.76 (95% CI: 0.68-0.86; p[lt]0.001). In a commercially-insured setting, treatment for epilepsy with LEV was associated with significantly less utilization and costs of common healthcare services than GBP. Rate and risk of AEs were lower in LEV compared to GBP. Data suggest better adherence to LEV compared to GBP treatment. These differences may suggest that use of LEV could lead to cost control. (Supported by UCB Pharma S.A.)