Epilepsy surgery trends in the United States, 1990-2008

Abstract

Objective: To examine national time trends of resective surgery for the treatment of medically refractory epilepsy before and after Class I evidence demonstrating its efficacy and subsequent practice guidelines recommending early surgical evaluation.

Methods: We performed a population-based cohort study with time trends of patients admitted to US hospitals for medically refractory focal epilepsy between 1990 and 2008 who did or did not undergo lobectomy, as reported in the Nationwide Inpatient Sample.

Results: Weighted data revealed 112,026 hospitalizations for medically refractory focal epilepsy and 6,653 resective surgeries (lobectomies and partial lobectomies) from 1990 to 2008. A trend of increasing hospitalizations over time was not accompanied by an increase in surgeries, producing an overall trend of decreasing surgery rates (F = 13.6, p < 0.01). Factors associated with this trend included a decrease in epilepsy hospitalizations at the highest-volume epilepsy centers, and increased hospitalizations to lower-volume hospitals that were found to be less likely to perform surgery. White patients were more likely to have surgery than racial minorities (relative risk [RR], 1.13; 95% confidence interval [CI], 1.10-1.17), and privately insured individuals were more likely to receive lobectomy than those with Medicaid or Medicare (RR, 1.28; 95% CI, 1.25-1.30).

Conclusion: Despite Class I evidence and subsequent practice guidelines, the utilization of lobectomy has not increased from 1990 to 2008. Surgery continues to be heavily underutilized as a treatment for epilepsy, with significant disparities by race and insurance coverage. Patients who are medically refractory after failing 2 antiepileptic medications should be referred to a comprehensive epilepsy center for surgical evaluation.

Figure 1. Trends of hospitalizations for medically refractory focal epilepsy and lobectomy procedure rates, 1990–2008

(A) Hospitalizations for medically refractory focal epilepsy (left y-axis) increased from 1990 to 2008 (F = 37.5, p < 0.001). No significant trend was observed in the annual number of lobectomies (right y-axis) performed on this these patients over the same period (F = 0.4, p = 0.56). (B) The percent of intractable epilepsy hospitalizations including lobectomy showed a downward trend over time (F = 13.6, p < 0.01). Dashed line represents publication year (2001) of a randomized, controlled trial examining surgical lobectomy for uncontrolled epilepsy.