Abstracts

Rationale: Research has shown that health care costs decline after successful epilepsy surgery in the short-term, but the long-term impact on costs and utilization is unknown. Our objective was to compare long-term health care expenditures, utilization, and mortality in those receiving resective surgical treatment for uncontrolled epilepsy versus non-surgical controls.Methods: This was a retrospective longitudinal cohort study of Medicaid beneficiaries with epilepsy from 2000 - 2008. The study population included 7,835 persons with uncontrolled focal epilepsy age 18 to 64 years, with an average follow-up time of 5 years. Of these, 135 received surgery during the study period. To account for selection bias, we used risk-set optimal pairwise matching on a time-varying propensity score, and inverse probability of treatment weighting. Repeated measures generalized linear models were used to model utilization and cost outcomes. Cox proportional hazard was used to model survival.Results: The mean cost difference among the treated group was $13,454 after weighting and $6,806 after risk-set matching. The incidence rate ratio of inpatient, emergency room, and outpatient utilization was lower among the surgical group. This effect was significant for all analyses except risk-set matching. There was no significant difference in mortality after adjustment. Among surgical cases, subjects had $6,481 (95%CI: ±2,241) reduction in annual costs, 0.58 (±0.21) fewer inpatient visits, 2.93 (±0.84) fewer outpatient visits, and 1.03 (±0.42) fewer ER visits per year, compared to before surgery.Conclusions: Subjects that underwent epilepsy surgery had lower health care costs and health care utilization. These findings support that epilepsy surgery can yield substantial health care cost savings to payers like Medicaid.