title: A Model Based Cost-Effectiveness Analysis of Routine Genotyping for CYP2D6 among Older, Depressed Inpatients Starting Nortriptyline Pharmacotherapy.
abstract: OBJECTIVE
  Genotyping for CYP2D6 has the potential to predict differences in metabolism of nortriptyline. This information could optimize pharmacotherapy. We determined the costs and effects of routine genotyping for old aged Dutch depressed inpatients.
  
  
  METHODS
  With a decision-tree, we modelled the first 12 weeks of nortriptyline therapy. Direct costs of genotyping, hospitalization, therapeutic drug monitoring and drugs were included. Based on genotype, patients could be correctly, sub-, or supratherapeutically dosed. Improvement from sub- or supratherapeutically dosed patients to correctly dosed patients was simulated, assuming that genotyping would prevent under- or overdosing of patients. In the base case, this improvement was assumed to be 35%. A probabilistic sensitivity analysis (PSA) was performed to determine uncertainty around the incremental cost-effectiveness ratio (ICER).
  
  
  RESULTS
  In the base case analysis, costs for genotyping were assumed €200 per test with a corresponding ICER at €1 333 000 per QALY. To reach a €50 000 per QALY cut-off, genotyping costs should be decreased towards €40 per test. At genotyping test costs < €35 per test, genotyping was dominant. At test costs of €17 per test there was a 95% probability that genotyping was cost-effective at €50 000 per QALY.
  
  
  CONCLUSIONS
  CYP2D6 genotyping was not cost-effective at current genotyping costs at a €50 000 per QALY threshold, however at test costs below €40, genotyping could be costs-effective.
authors.affiliation: University of Groningen, Groningen Institute of Pharmacy, Unit of PharmacoTherapy, -Epidemiology and -Economics (PTE2), Groningen, the Netherlands.
authors.forename: Elizabeth J J
authors.initials: EJ
authors.lastname: Berm
authors.affiliation: University of Groningen, Groningen Institute of Pharmacy, Unit of PharmacoTherapy, -Epidemiology and -Economics (PTE2), Groningen, the Netherlands.
authors.forename: Judith J
authors.initials: JJ
authors.lastname: Gout-Zwart
authors.affiliation: University of Groningen, Groningen Institute of Pharmacy, Unit of PharmacoTherapy, -Epidemiology and -Economics (PTE2), Groningen, the Netherlands.
authors.forename: Jos
authors.initials: J
authors.lastname: Luttjeboer
authors.affiliation: University of Groningen, Groningen Institute of Pharmacy, Unit of PharmacoTherapy, -Epidemiology and -Economics (PTE2), Groningen, the Netherlands.|University of Groningen, University Medical Center Groningen, Department of Clinical Pharmacy and Pharmacology, Groningen, the Netherlands.
authors.forename: Bob
authors.initials: B
authors.lastname: Wilffert
authors.affiliation: University of Groningen, Groningen Institute of Pharmacy, Unit of PharmacoTherapy, -Epidemiology and -Economics (PTE2), Groningen, the Netherlands.|University Medical Center Groningen (UMCG), Institute for Science in Healthy Aging & HealthcaRE (SHARE), Groningen, the Netherlands.|University Medical Center Groningen (UMCG), Department of Epidemiology, Groningen, the Netherlands.
authors.forename: Maarten J
authors.initials: MJ
authors.lastname: Postma
mesh_terms: D003362:Cost-Benefit Analysis; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D003663:Decision Trees; D003863:Depression / Q000188:drug therapy* / Q000201:enzymology / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D060005:Genotyping Techniques / Q000191:economics*; D006760:Hospitalization; D006801:Humans; D008875:Middle Aged; D008962:Models, Theoretical; D009661:Nortriptyline / Q000009:adverse effects / Q000627:therapeutic use*; D011336:Probability; D019057:Quality-Adjusted Life Years; D012449:Safety; D016896:Treatment Outcome
chemical_list: D009661:Nortriptyline; D019389:Cytochrome P-450 CYP2D6