Abstract

We retrospectively analyzed the effects of vagus nerve stimulation (VNS) therapy on utilization of medical services by 138 patients in a large staff-model health maintenance organization. We compared average quarterly rates for 12 months before device implantation with quarterly rates during 48 months of follow-up. Wilcoxon matched-pairs signed-ranks tests comparing pre-VNS with post-VNS utilization rates showed statistically significant reductions in numbers of emergency department visits, hospitalizations, and hospital lengths of stay, beginning with the first quarter after implantation (P < 0.05 for all post-implantation quarters for these three aspects). For the first two quarters after implantation, the average number of outpatient visits was significantly greater than the pre-implant quarterly average (quarter 1: P < 0.0001; quarter 2: P = 0.0067), but the average was 12.2% less by the fourth quarter of the first year after implantation and significantly less beginning with the first quarter of the second year (P = 0.0017) and continuing through the end of the study (P < 0.0001 for all subsequent quarters). A comparison of time spent on epilepsy-related tasks during the year before implantation with the year after implantation also revealed significant decreases in the average number of days on which patients could not work because of health-related concerns, from 3.67 to 1.04 days (P = 0.002, paired Student’s t test) and the average time spent caring for health problems, from 352.6 to 136.1 minutes per week (P < 0.001). VNS therapy had a positive effect on both the utilization of health care services and the time spent on epilepsy-related tasks for these patients with pharmacoresistant epilepsy.

Keywords: Vagus nerve stimulation therapy; Epilepsy; Utilization; Pharmacoresistant

Cyberonics, Inc supported this research through an unrestricted grant.
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