title: Cost-effectiveness of the ketogenic diet and vagus nerve stimulation for the treatment of children with intractable epilepsy.
abstract: OBJECTIVE
  The objective of this study was to estimate the expected cost-utility and cost-effectiveness of the ketogenic diet (KD), vague nerve stimulation (VNS) and care as usual (CAU), using a decision analytic model with a 5-year time horizon.
  
  
  METHODS
  A Markov decision analytical model was constructed to estimate the incremental costs, quality-adjusted life years (QALYs) and successfully treated patient (i.e. 50% or more seizure reduction) of the treatment strategies KD, VNS and CAU, from a health care perspective. The base case considered children with intractable epilepsy (i.e. two or more antiepileptic drugs had failed) aged between 1 and 18 years. Data were derived from literature and expert meetings. Deterministic and probabilistic sensitivity analyses were performed.
  
  
  RESULTS
  Our results suggest that KD is more effective and less costly, and thus cost-effective compared with VNS, after 12 months. However, compared to CAU, neither KD nor VNS are cost-effective options, they are both more effective but also more expensive (€346,899 and €641,068 per QALY, respectively). At 5 years, VNS is cost-effective compared with KD and CAU (€11,378 and €68,489 per QALY, respectively) and has a 51% probability of being cost-effective at a ceiling ratio of €80,000 per QALY.
  
  
  CONCLUSIONS
  Our results suggest that on average the benefits of KD and VNS fail to outweigh the costs of the therapies. However, these treatment options should not be ignored in the treatment for intractable epilepsy in individual or specific groups of patients. There is a great need for high quality comparative studies with large patient samples which allow for subgroup analyses, long-term follow-up periods and outcome measures that measure effects beyond seizure frequency (e.g. quality of life). When this new evidence becomes available, reassessment of the cost-effectiveness of KD and VNS in children with intractable epilepsy should be carried out.
authors.affiliation: Department of Health Services Research, CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands; Department of Research and Development, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands; MHENS School of Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands. Electronic address: Reina.dekinderen@maastrichtuniversity.nl.
authors.forename: Reina J A
authors.initials: RJ
authors.lastname: de Kinderen
authors.affiliation: Department of Research and Development, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands. Electronic address: debby.postulart@gmail.com.
authors.forename: Debby
authors.initials: D
authors.lastname: Postulart
authors.affiliation: Department of Research and Development, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands; MHENS School of Mental Health & Neuroscience, Maastricht University, Maastricht, The Netherlands; Department of Behavioral Sciences, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands; ACE Academic Center for Epileptology, Kempenhaeghe/Maastricht University Medical Center, Heeze/Maastricht, The Netherlands; Faculty of Electrical Engineering, University of Technology, Eindhoven, The Netherlands. Electronic address: aldenkampB@kempenhaeghe.nl.
authors.forename: Albert P
authors.initials: AP
authors.lastname: Aldenkamp
authors.affiliation: Department of Health Services Research, CAPHRI School for Public Health and Primary Care, Maastricht University, Maastricht, The Netherlands; Trimbos Institute, National Institute of Mental Health and Addiction, Utrecht, The Netherlands. Electronic address: s.evers@maastrichtuniversity.nl.
authors.forename: Silvia M A A
authors.initials: SM
authors.lastname: Evers
authors.affiliation: Department of Research and Development, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands; ACE Academic Center for Epileptology, Kempenhaeghe/Maastricht University Medical Center, Heeze/Maastricht, The Netherlands; Department of Neurology, Academic Center for Epileptology Kempenhaeghe, Heeze, The Netherlands. Electronic address: D.lambrechts@kempenhaeghe.nl.
authors.forename: Danielle A J E
authors.initials: DA
authors.lastname: Lambrechts
authors.affiliation: Department of Research and Development, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands; ACE Academic Center for Epileptology, Kempenhaeghe/Maastricht University Medical Center, Heeze/Maastricht, The Netherlands; Department of Neurology, Academic Center for Epileptology Kempenhaeghe, Heeze, The Netherlands. Electronic address: louwA@kempenhaeghe.nl.
authors.forename: Anton J A de
authors.initials: AJ
authors.lastname: Louw
authors.affiliation: Department of Research and Development, Epilepsy Center Kempenhaeghe, Heeze, The Netherlands; ACE Academic Center for Epileptology, Kempenhaeghe/Maastricht University Medical Center, Heeze/Maastricht, The Netherlands; Department of Neurology, Academic Center for Epileptology Kempenhaeghe, Heeze, The Netherlands. Electronic address: MajoieM@kempenhaeghe.nl.
authors.forename: Marian H J M
authors.initials: MH
authors.lastname: Majoie
authors.affiliation: Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands. Electronic address: Janneke.grutters@radboudumc.nl.
authors.forename: Janneke P C
authors.initials: JP
authors.lastname: Grutters
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D055423:Diet, Ketogenic / Q000191:economics*; D004827:Epilepsy / Q000191:economics* / Q000628:therapy*; D006801:Humans; D007223:Infant; D008390:Markov Chains; D017059:Models, Econometric; D019057:Quality-Adjusted Life Years; D055536:Vagus Nerve Stimulation / Q000191:economics*
keywords: Economic evaluation; Intractable epilepsy; Ketogenic diet; Modeling; QALY; Vagus nerve stimulation