title: A study of the impact of VNS on health care utilisation in England.
abstract: OBJECTIVE
  To compare hospital service use before and after VNS therapy implantation in a sample of drug-resistant people with epilepsy.
  
  
  METHODS
  The before and after study was performed using anonymised Hospital Episode Statistics (HES) data from one year before to 3 years after implantation in 321 patients from data collected between April 2009 to July 2011. Episodes relating to out-patient clinic, Accident and Emergency (A&E) department attendance, hospital admissions and length of stay were collected and compared. Descriptive statistics are used to summarise patient demographics, patient pathways and resource usage before and after VNS implantation. Means and proportions were reported on continuous variables, proportion and frequency on categorical variables. Trends of activity over time were determined using before and after VNS comparisons and tested with the Wilcoxon Signed-rank (WSR) test.
  
  
  RESULTS
  The summary statistics indicate a drop in resource use in terms of in-patient bed-days (21% decrease), elective in-patient episodes (7% decrease) and non-elective in-patient episodes (14% decrease). There was an increase in the quarterly average out-patient appointments by 12%. The A&E attendance outcome recorded a mean increase in quarterly attendances of 9% but a slight decrease when subject to a signed rank test. These contradictory results should therefore be treated with caution.
  
  
  CONCLUSIONS
  VNS Therapy may be associated with an overall reduction in health service resource use.
authors.affiliation: HCD Economics, Daresbury, UK.
authors.forename: Tom
authors.initials: T
authors.lastname: Burke
authors.affiliation: HCD Economics, Daresbury, UK; University of Chester, Chester, UK.
authors.forename: David
authors.initials: D
authors.lastname: Hughes
authors.affiliation: Cyberonics, Inc., Houston, TX, USA.
authors.forename: John
authors.initials: J
authors.lastname: Forsey
authors.affiliation: Cyberonics, Inc., Houston, TX, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Bunker
authors.affiliation: Neurosurgeon Royal Hallamshire Hospital, Sheffield, UK.
authors.forename: Dev
authors.initials: D
authors.lastname: Bhattacharya
authors.affiliation: University College Cork, Cork, Ireland. Electronic address: henry.smithson@ucc.ie.
authors.forename: W Henry
authors.initials: WH
authors.lastname: Smithson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000553:Ambulatory Care / Q000706:statistics & numerical data*; D002648:Child; D002675:Child, Preschool; D000069279:Drug Resistant Epilepsy / Q000628:therapy*; D004739:England; D005260:Female; D006295:Health Resources / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009819:Office Visits; D055536:Vagus Nerve Stimulation; D055815:Young Adult
keywords: Before and after; Health utilisation; VNS