title: Cost analysis of the adverse reactions of bipolar disorder treatment with aripiprazole and olanzapine in Spain.
abstract: OBJECTIVE
  This study investigates the healthcare costs of adverse events (AE) associated with treatment of bipolar disorder with two atypical oral antipsychotics (AOA): aripiprazole (ARI) and olanzapine (OLA).
  
  
  METHODS
  A cost analysis using a Markov model considering the following health states was performed: no existence of adverse events (NAE); extrapyramidal symptoms (EPS); weight gain (WG); and sexual dysfunction (SD). Transition probabilities amongst health states were estimated from meta-analyses of clinical trials and from a retrospective Spanish study. The healthcare costs associated to each health state were obtained from a published Spanish study. The minimum acquisition cost per mg of the mean daily dose for each AOA was used. This is considered to be a relevant efficiency criterion in Hospital Pharmacy Departments. The time horizon applied in the analysis was 12 months. A probabilistic sensitivity analysis was performed for all the variables involved in the analysis with Monte Carlo simulations. All costs were updated to 2013 costs using the Spanish Health System price index.
  
  
  RESULTS
  In comparison with OLA, treatment with ARI generates annual average cost savings per patient of ¤289 (CI95% ¤271; ¤308). In the hypothetical scenario in which we assume that ARI may have a similar rate of sexual dysfunction as that of quetiapine (i.e. the lowest rate amongst AOAs), the additional cost per patient would be ¤323 (CI95% ¤330; ¤317).
  
  
  CONCLUSIONS
  The results of this analysis show that patients treated with aripiprazole demonstrate lower adverse events costs in comparison to olanzapine. This difference may generate significant cost savings in the Spanish health system in the treatment of patients affected by bipolar disorders. The robustness of the results was tested via a probabilistic analysis.
authors.affiliation: Health Value. Madrid.
authors.forename: Carlos
authors.initials: C
authors.lastname: Rubio-Terrés
authors.affiliation: Health Value. Madrid.
authors.forename: Darío
authors.initials: D
authors.lastname: Rubio-Rodríguez
authors.affiliation: Servicio de Psiquiatría Hospital Universitario Puerta de Hierro. Madrid.
authors.forename: Enrique
authors.initials: E
authors.lastname: Baca-Baldomero
mesh_terms: D014150:Antipsychotic Agents / Q000191:economics* / Q000627:therapeutic use*; D000068180:Aripiprazole / Q000191:economics* / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000191:economics* / Q000627:therapeutic use*; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000191:economics*; D017048:Health Care Costs; D006801:Humans; D008390:Markov Chains; D000077152:Olanzapine; D013030:Spain
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D000068180:Aripiprazole; D000077152:Olanzapine