title: Rehospitalization and emergency department use rates before and after vagus nerve stimulation for epilepsy: use of state databases to provide longitudinal data across multiple clinical settings.
abstract: OBJECTIVE
  Data regarding rehospitalization and emergency department (ED) visits following vagus nerve stimulation (VNS) present data analysis challenges. We present a method that uses California's multiple databases to more completely assay VNS efficacy.
  
  
  METHODS
  The Healthcare Cost and Utilization Project's California Inpatient and Ambulatory Surgery databases were assayed for all VNS surgeries from 2005 to 2009. Patients were selected by epilepsy diagnosis codes and VNS procedure codes. Patients (total N = 629) were tracked across multiple databases using unique identifiers. Thirty-day and one-year post-implantation rates of VNS complication and healthcare visits were abstracted, along with one-year preoperative hospital and ED use. Statistics included correction for multiple comparisons.
  
  
  RESULTS
  The one-year reoperation rate for adult patients (N = 536) was 3.9%; during the second year, an additional 3.2% of patients had reoperations. Within the first 30 days, <2% of patients experienced a complication. Four percent of patients were readmitted to a hospital, and 11.6% of patients visited an ED. The most common reason for rehospitalization or ED visit was seizure. In the first year after VNS, total seizure-related visits (hospitalization and ED) were 17% lower (2.12 visits per year to 1.71; p = 0.03). In the second year following VNS, seizure-related visits were 42% lower (2.21 visits per year to 1.27, p = 0.01). Pediatric patients (N = 93) had comparable results.
  
  
  CONCLUSIONS
  VNS surgery has low rates of complications and reoperations and is associated with reduced incidence of seizure-related ED visits and hospital admissions in the first and second postoperative years.
authors.affiliation: Department of Neurosurgery, Stanford University Hospitals and Clinics, Stanford, CA, USA.
authors.forename: Paul S A
authors.initials: PS
authors.lastname: Kalanithi
authors.forename: Robert T
authors.initials: RT
authors.lastname: Arrigo
authors.forename: Pelu
authors.initials: P
authors.lastname: Tran
authors.forename: Melanie Hayden
authors.initials: MH
authors.lastname: Gephart
authors.forename: Lawrence
authors.initials: L
authors.lastname: Shuer
authors.forename: Robert
authors.initials: R
authors.lastname: Fisher
authors.forename: Maxwell
authors.initials: M
authors.lastname: Boakye
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002140:California; D016208:Databases, Factual; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D004827:Epilepsy / Q000628:therapy*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055536:Vagus Nerve Stimulation / Q000009:adverse effects / Q000706:statistics & numerical data; D055815:Young Adult
keywords: database; epilepsy; outcomes; rehospitalization; vagus nerve stimulation