Rationale: Approximately 30% of patients with epilepsy have drug-resistant epilepsy (DRE) (Kwan and Brodie, 2000). Despite the long-term proven effectiveness of vagus nerve stimulation VNS Therapy® (Englot et al., 2016), the time to initial implant occurs approximately 20 years after initial diagnosis (Janszky et al., 2005) and after an average of 7 anti-epileptic drugs (AEDs) tried (Handforth et al., 1998). The objective of this study was to estimate, from the perspective of a managed care organization in the US, the budget impact and effect on health outcomes of expanded use of VNS Therapy among patients ≥ 12 years of age with DRE with partial onset seizures.
Methods: An Excel model was developed to compare the costs of continued AED treatment with the costs of VNS Therapy in addition to AED therapy. The number of people eligible for VNS Therapy was estimated using published prevalence data and an estimate of the percentage of eligible patients currently without VNS. Costs included VNS device, placement, programming, and battery changes; adverse events associated with VNS device (cough, voice alteration, device removal resulting from surgical site infection); AEDs; and seizure-related costs affected by seizure frequency, which affects resource utilization (i.e., hospitalizations, ED visits, neurologist visits). To estimate the potential savings with VNS Therapy due to a reduction in seizure frequency, the budget-impact model used the results of an underlying semi-Markov model (LivaNova, 2016) to estimate seizure-related costs (hospitalizations, ED visits, and neurologist visits) by seizure frequency. Transitions occurred among 4 health states, defined by number of seizures per month (i.e., seizure-free, ≤ 1, > 1 to < 10, ≥ 10) on a 3-month cycle based on published clinical trials, and registry data.
Results: VNS Therapy resulted in a net cost savings due to the expected reduction in seizure frequency (Figure 1). On average, VNS Therapy resulted in a net cost savings of $77,480 per patient over 5 years. The initial cost of the VNS device, placement, and programming ($39,309) is offset in 1.7 years after VNS device placement (Figure 2). Reductions in hospitalizations are the main contributor to the cost savings with VNS Therapy.
Conclusion: VNS Therapy is a proven intervention that offers a long-term solution for patients with DRE by reducing seizure frequency, which leads to lower resource utilization and lower costs.
