title: Development and validation of a Markov microsimulation model for the economic evaluation of treatments in osteoporosis.
abstract: OBJECTIVE
  Markov models are increasingly used in economic evaluations of treatments for osteoporosis. Most of the existing evaluations are cohort-based Markov models missing comprehensive memory management and versatility. In this article, we describe and validate an original Markov microsimulation model to accurately assess the cost-effectiveness of prevention and treatment of osteoporosis.
  
  
  METHODS
  We developed a Markov microsimulation model with a lifetime horizon and a direct health-care cost perspective. The patient history was recorded and was used in calculations of transition probabilities, utilities, and costs. To test the internal consistency of the model, we carried out an example calculation for alendronate therapy. Then, external consistency was investigated by comparing absolute lifetime risk of fracture estimates with epidemiologic data.
  
  
  RESULTS
  For women at age 70 years, with a twofold increase in the fracture risk of the average population, the costs per quality-adjusted life-year gained for alendronate therapy versus no treatment were estimated at €9105 and €15,325, respectively, under full and realistic adherence assumptions. All the sensitivity analyses in terms of model parameters and modeling assumptions were coherent with expected conclusions and absolute lifetime risk of fracture estimates were within the range of previous estimates, which confirmed both internal and external consistency of the model.
  
  
  CONCLUSIONS
  Microsimulation models present some major advantages over cohort-based models, increasing the reliability of the results and being largely compatible with the existing state of the art, evidence-based literature. The developed model appears to be a valid model for use in economic evaluations in osteoporosis.
authors.affiliation: Department of Economics, University of Liège, Liège, Belgium.
authors.forename: Mickaël
authors.initials: M
authors.lastname: Hiligsmann
authors.forename: Olivier
authors.initials: O
authors.lastname: Ethgen
authors.forename: Olivier
authors.initials: O
authors.lastname: Bruyère
authors.forename: Florent
authors.initials: F
authors.lastname: Richy
authors.forename: Henry-Jean
authors.initials: HJ
authors.lastname: Gathon
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Reginster
mesh_terms: D000368:Aged; D019386:Alendronate / Q000191:economics / Q000627:therapeutic use; D050071:Bone Density Conservation Agents / Q000191:economics* / Q000627:therapeutic use; D003362:Cost-Benefit Analysis; D016527:Drug Costs; D005260:Female; D050723:Fractures, Bone / Q000191:economics / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D008390:Markov Chains; D017059:Models, Econometric; D010024:Osteoporosis / Q000150:complications / Q000188:drug therapy / Q000191:economics* / Q000517:prevention & control; D011336:Probability; D019057:Quality-Adjusted Life Years; D015203:Reproducibility of Results
chemical_list: D050071:Bone Density Conservation Agents; D019386:Alendronate