Abstracts

Rationale: Seizures in patients with epilepsy are commonly treated with anti-epileptic drugs (AEDs), but ~30-40% of patients do not achieve adequate seizure control, predisposing them to severe health risks, impaired quality of life and higher healthcare costs. While previous studies have focused on the healthcare burden of adjunctively-treated patients ( 2 AEDs), literature on the healthcare resource utilization of patients with different levels of epilepsy control is lacking. This study aimed to evaluate the healthcare resource utilization of adjunctively-treated patients in the uncontrolled (UNC), well-controlled (WLC), and intermediate-controlled (INC) epilepsy categories.Methods: The MarketScan retrospective database was used to analyze the healthcare costs of patients with epilepsy between January 2007 and December 2011. Included patients had 1 diagnosis codes for epilepsy (ICD-9 345.xx), were 18 years old, and were treated with at least one add-on AED within 60 days of first-line treatment. Patients were grouped into three cohorts: WLC who had no change in AED therapy and no epilepsy-related emergency room or inpatient visits; UNC who had two or more consecutive changes in AED (treatment switch or add-on) occurring at least 30 days apart and one or more epilepsy-related emergency room (ER) or inpatient (IP) visit (index date, imputed for WLC and INC); and INC patients that were not otherwise classified as UNC or WLC. All patients were required to have 180 days pre-index, and 365 post-index continuous enrolment. The groups were matched to pairs using propensity score matching in a 1:1 ratio. A conditional multivariate Poisson regression was used to calculate adjusted incidence rates (IR), incidence rate ratios (IRR), and corresponding 95% confidence intervals (CI) of healthcare resource utilization on a per person per year basis.Results: From a total of 26,625 patients: 521 (2%) were UNC, 3,980 were WLC (15%), and 22,124 were INC (83%). A total of 521 matched pairs were included in the analysis. The mean age was 49 years (SD 15.1); 59% were female. The UNC group used significantly more AEDs (0.8 vs. 0.5; 0.5), and had significantly more outpatient visits (47.3 vs. 39.3; 44.7) and neurologist visits (1.4 vs. 1.0; 1.2) compared to the WLC and INC groups, respectively (p<0.001 for all comparisons) (Table). The UNC had significantly more ER visits (3.1 vs. 0.4; p<0.0001), IP visits (1.6 vs. 0.2; p<0.001), and longer IP stays (7.8 vs. 0.6 days; p<0.001) compared to the WLC, but fewer IP stays (1.6 vs. 1.8; p<0.05) compared to the INC. No statistically significant differences were seen for ER visits and length IP stay between the UNC and INC.Conclusions: This study shows that uncontrolled epilepsy involves a significantly higher healthcare utilization compared to well-controlled epilepsy, and that intermediate levels of epilepsy control result in similar increases in utilization. These findings suggest that even small departures from optimal seizure control are associated with a marked increase in health resource utilization among epilepsy patients.