title: Cost-effectiveness analysis of valsartan versus losartan and the effect of switching.
abstract: OBJECTIVE
  Losartan will shortly become generic, and this may encourage switching to the generic drug. However, valsartan was shown in a meta-analysis to be statistically superior in lowering blood pressure (BP) to losartan. This paper examines the costs of treatment with these two drugs and the potential consequences of switching established valsartan patients to generic losartan.
  
  
  METHODS
  A US payer cost-effectiveness model was developed incorporating the risk of cardiovascular disease (CVD) events related to systolic blood pressure (SBP) control comparing valsartan to continual losartan and switching from valsartan to generic losartan. The model, based upon a meta-analysis by Nixon et al. and Framingham equations, included first CVD event costs calculated from US administrative data sets and utility values from published sources. The modeled outcomes were number of CVD events, costs and incremental cost per quality-adjusted life-year (QALY) and life-year (LY).
  
  
  RESULTS
  Fewer patients had fatal and non-fatal CVD events with valsartan therapy compared with continual losartan and with patients switched from valsartan to generic losartan. The base-case model results indicated that continued treatment with valsartan had an incremental cost-effectiveness ratio of $27,268 and $25,460 per life year gained, and $32,313 and $30,170 per QALY gained, relative to continual losartan and switching treatments, respectively. Sensitivity analyses found that patient discontinuation post-switching was a sensitive parameter. Including efficacy offsets with lowered adherence or discontinuation resulted in more favorable ratios for valsartan compared to switching therapy.
  
  
  CONCLUSIONS
  The model does not evaluate post-primary CVD events and considers change in SBP from baseline level as the sole predictor of CVD risk.
  
  
  CONCLUSIONS
  Valsartan appears to be cost-effective compared to switching to generic losartan and switching to the generic drug does not support a cost offset argument over the longer term. Physicians should continue to consider the needs of individual patient and not cost offsets.
authors.affiliation: United BioSource Corporation, Bethesda, MD 20814, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Baker
authors.forename: Jowern
authors.initials: J
authors.lastname: Goh
authors.forename: Atholl
authors.initials: A
authors.lastname: Johnston
authors.forename: Heather
authors.initials: H
authors.lastname: Falvey
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Brede
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Brown
mesh_terms: D000959:Antihypertensive Agents / Q000191:economics* / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000188:drug therapy / Q000401:mortality; D003362:Cost-Benefit Analysis; D057915:Drug Substitution / Q000191:economics*; D005252:Fees, Pharmaceutical; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D007349:Insurance, Health, Reimbursement; D019808:Losartan / Q000191:economics* / Q000627:therapeutic use; D017063:Outcome Assessment, Health Care; D019057:Quality-Adjusted Life Years; D013777:Tetrazoles / Q000191:economics* / Q000627:therapeutic use; D014481:United States / Q000453:epidemiology; D014633:Valine / Q000031:analogs & derivatives* / Q000191:economics / Q000627:therapeutic use; D000068756:Valsartan
chemical_list: D000959:Antihypertensive Agents; D013777:Tetrazoles; D000068756:Valsartan; D014633:Valine; D019808:Losartan