title: Clinical outcomes, quality of life, and costs associated with implantation of vagus nerve stimulation therapy in pediatric patients with drug-resistant epilepsy.
abstract: BACKGROUND
  VNS (Vagus Nerve Stimulation Therapy) is approved in the USA to treat refractory epilepsy as adjunctive to antiepileptic drugs (AEDs) in patients ≥12 years with complex partial seizures.
  
  
  OBJECTIVE
  To evaluate clinical outcomes, quality-adjusted life years (QALY), and costs associated with VNS in pediatric patients with drug-resistant epilepsy in a real-world setting.
  
  
  METHODS
  A retrospective analysis was conducted using Medicaid data (USA). Patients had ≥1 neurologist visits with epilepsy diagnosis (ICD-9 345.xx, 780.3x), ≥1 procedure claims for VNS implantation, ≥1 AEDs, ≥6-months of Pre- and Post-VNS continuous enrollment. Pre-VNS period was 6-months and Post-VNS period extended from implantation until device removal, death, Medicaid disenrollment, or study end (up to 3 years). Incidence rate ratios (IRR) and costs ($2010) were estimated. QALYs were estimated using number of seizure-related events.
  
  
  RESULTS
  For patients 1-11 years old (N = 238), hospitalizations and emergency room visits were reduced Post-VNS vs. Pre-VNS (adjusted IRR = 0.73 [95% CI: 0.61-0.88] and 0.74 [95% CI: 0.65-0.83], respectively). Average total healthcare costs were lower Post-VNS vs. Pre-VNS ($18,437 vs. $18,839 quarterly [adjusted p = 0.052]). For patients 12-17 years old (N = 207), hospitalizations and status epilepticus events were reduced Post-VNS vs. Pre-VNS (adjusted IRR = 0.43 [95% CI: 0.34-0.54] and 0.25 [95% CI: 0.16-0.39], respectively). Average total healthcare costs were lower Post-VNS vs. Pre-VNS period ($14,546 vs. $19,695 quarterly [adjusted p = 0.002]). Lifetime QALY gain after VNS was 5.96 (patients 1-11 years) and 4.82 years (patients 12-17 years).
  
  
  CONCLUSIONS
  VNS in pediatric patients is associated with decreased resource use and epilepsy-related events, cost savings, and QALY gain.
authors.affiliation: Emory University School of Medicine, Atlanta, GA 30322, United States. sandra.helmers@emory.edu
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Helmers
authors.forename: Mei Sheng
authors.initials: MS
authors.lastname: Duh
authors.forename: Annie
authors.initials: A
authors.lastname: Guérin
authors.forename: Sujata P
authors.initials: SP
authors.lastname: Sarda
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Samuelson
authors.forename: Mark T
authors.initials: MT
authors.lastname: Bunker
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Olin
authors.forename: Stanley D
authors.initials: SD
authors.lastname: Jackson
authors.forename: Edward
authors.initials: E
authors.lastname: Faught
mesh_terms: D000927:Anticonvulsants / Q000191:economics / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D017046:Cost Savings / Q000191:economics; D004827:Epilepsy / Q000188:drug therapy / Q000191:economics / Q000628:therapy*; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007223:Infant; D008297:Male; D011788:Quality of Life / Q000523:psychology*; D019057:Quality-Adjusted Life Years; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States; D055536:Vagus Nerve Stimulation / Q000191:economics* / Q000523:psychology
chemical_list: D000927:Anticonvulsants