title: [The role of models in economic evaluation of healthcare].
abstract: BACKGROUND
  The information on which decision-making in healthcare is based --especially information on new drugs or technologies-- comes mainly from phase III clinical trials, which are carried out according to clinical efficacy criteria. Placebos are frequently used as comparators. Therefore, no clinical or economic evidence is usually available to assess the new product or technology in real-life practice (effectiveness). Efficiency is seldom evaluated either.
  
  
  METHODS
  The clinical evidence generated by clinical trials usually evaluates intermediate, not final clinical variables. This makes decision-making difficult, both for clinicians or health-care managers in areas as varied as financing drugs or technology, inclusion of these in a therapeutic formulary or in clinical pathways.
  
  
  CONCLUSIONS
  To obtain clinical and economic information, modelling techniques have been developed in the field of health economics. This study reviews the justification of the use of models, their characteristics, methodological requirements and steps followed for their construction and resolution, while Markov models are explained.
authors.affiliation: Departamento de Farmacoeconomía, GlaxoSmithKline, Tres Cantos, Madrid. j.rodriguez.015@recol.es
authors.forename: J M
authors.initials: JM
authors.lastname: Rodríguez Barrios
mesh_terms: D017326:Clinical Trials, Phase III as Topic / Q000191:economics*; D019091:Critical Pathways; D003659:Decision Making, Organizational; D005569:Formularies as Topic; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D008390:Markov Chains; D017059:Models, Econometric; D013673:Technology Assessment, Biomedical / Q000191:economics
vernacular_title: Papel de los modelos en las evaluaciones económicas en el campo sanitario.