title: Impact of vagus nerve stimulation on secondary care burden in children and adults with epilepsy: Review of routinely collected hospital data in England.
abstract: OBJECTIVE
  We evaluated the long-term medical and economic benefits of vagus nerve stimulation (VNS) therapy for 704 adults and children with epilepsy. A pre-post analysis was conducted using Hospital Episode Statistics (HES) data (April 2008-July 2014). Seven hundred and four patients with epilepsy diagnoses (ICD-10 G40.x or G41.x), one or more procedures for vagus nerve stimulator implantation, and six or more months of available HES data pre- and post-VNS were selected. The pre-VNS period averaged 39.1 months. The post-VNS period extended from implantation to device removal, death, or study end (up to six years), with a mean duration of 36.4 months. Incidence rate ratios (IRRs) and cost differences (£2014) were estimated. Mean age was 28.3 years.
  
  
  RESULTS
  Inpatient admissions decreased post-VNS compared with pre-VNS (adjusted IRR=0.81, P<0.001). Overall, outpatient consultations increased post-VNS compared with pre-VNS (adjusted IRR=1.34, P<0.001). However, outpatient consultations exhibited a decreasing trend in the post-VNS period (adjusted IRR=0.96, P<0.001), suggesting that much of the increased outpatient activity in the post-VNS period relates to follow-up management of the VNS device in the immediate period following implantation, with comparable outpatient resource burden at 36 months post-VNS. No significant changes in clinical events were observed; however, average epilepsy-related medical costs were lower post-VNS than pre-VNS (adjusted cost difference -£110 quarterly, P=0.001).
  
  
  CONCLUSIONS
  Vagus nerve stimulation is associated with increased outpatient resource utilization and decreased inpatient admissions, with a reduction in long-term epilepsy-related medical costs post-implantation.
authors.affiliation: HCD Economics, The Innovation Centre, Daresbury, Cheshire WA44FS, UK. Electronic address: charlotte.camp@hcdeconomics.com.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Camp
authors.affiliation: Department of General Practice, University College Cork, Western Rd., Cork, Ireland. Electronic address: henry.smithson@ucc.ie.
authors.forename: William Henry
authors.initials: WH
authors.lastname: Smithson
authors.affiliation: Cyberonics, Inc., 100 Cyberonics Blvd., Houston, TX 77058, USA. Electronic address: mark.bunker@cyberonics.com.
authors.forename: Mark
authors.initials: M
authors.lastname: Bunker
authors.affiliation: HCD Economics, The Innovation Centre, Daresbury, Cheshire WA44FS, UK. Electronic address: tom.burke@hcdeconomics.com.
authors.forename: Tom
authors.initials: T
authors.lastname: Burke
authors.affiliation: HCD Economics, The Innovation Centre, Daresbury, Cheshire WA44FS, UK; Faculty of Health and Social Care, University of Chester, UK. Electronic address: david@hcdeconomics.com.
authors.forename: David
authors.initials: D
authors.lastname: Hughes
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017281:Cost of Illness; D020878:Device Removal; D004567:Electrodes, Implanted; D004739:England; D004827:Epilepsy / Q000150:complications / Q000191:economics / Q000628:therapy*; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data; D006295:Health Resources / Q000706:statistics & numerical data; D006760:Hospitalization / Q000191:economics; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D012189:Retrospective Studies; D016896:Treatment Outcome; D055536:Vagus Nerve Stimulation / Q000191:economics / Q000379:methods*; D055815:Young Adult
keywords: Cost savings; Costs; Economics; Outcomes; Resource utilization; Vagus nerve stimulation