OBJECTIVES: To estimate the cost-effectiveness of vagus nerve stimulation (VNS) as an adjunctive therapy to anti-seizure medication (ASMs) when compared with a strategy of ASMs alone for the management of drug resistant epilepsy (DRE).

METHODS: A five health state cohort transition model was developed, with a 10-year time horizon, a 3-month cycle length and an English National Health Service perspective. Health states were defined by a percentage reduction in seizure frequency and aligned with randomised trial data informing the first cycle transition probabilities. Thereafter, non-VNS patients remained in state, while a systematic literature review informed further VNS patient transitions up to year 2, after which they remained in state (subject to death or device discontinuation). Extrapolation of registered VNS implant Kaplan-Meier data informed explantation and replacement probabilities. Health state utilities were age and gender adjusted. Published estimates, combined with trial data regarding mean seizure frequency, informed health state resource use. In addition to the base case analysis, scenarios, one-way deterministic and probabilistic sensitivity analyses were undertaken.

RESULTS: Adjunctive VNS has an incremental cost-effectiveness ratio of £17,711 per quality-adjusted life year (QALY) when compared to a strategy of ASMs alone. Results were most sensitive to unit costs of inpatient care, with VNS expected to be dominant if the cost of a non-elective care admission exceeded £2,225. Using the UK National Institute of Health and Care Excellence threshold of £20,000 to £30,000 per QALY, VNS was cost-effective in the majority of scenarios evaluated, inclusive of varying the costs of device implantation, replacement and explantation by 15 percent.

CONCLUSIONS: Management of DRE with VNS is a cost-effective option in comparison to ASM therapy alone. This finding is driven by a reduced seizure frequency with VNS, which is consequently expected to improve a patient's health-related quality of life and reduce downstream medical costs.