title: Using cost-effectiveness/cost-benefit analysis to allocate health resources: a level playing field for prevention?
abstract: BACKGROUND
  Prevention is being promoted as a means to improve health status and to save health care costs. Economic evaluations of prevention (i.e., cost-effectiveness and cost-benefit analyses) indicate that some prevention activities, like many treatments, do not save money, although many are relatively cost-effective. It has been suggested, however, that prevention is held to a higher standard than treatment because prevention programs are expected to demonstrate cost savings, and that the methods of economic evaluation understate the cost-effectiveness of prevention. Although the converse assertion is less commonly made, economic evaluations may also overstate the cost-effectiveness of prevention. The purpose of this article is to examine how the methods of economic evaluation may systematically understate, or overstate, the cost-effectiveness (or net benefits) of prevention.
  
  
  METHODS
  We examine three key methods: (1) how future costs and benefits are valued ("discounting"), (2) how costs and benefits to people beyond those who are the users of prevention are valued ("externalities"), and (3) how nonmonetary costs and benefits to individuals are valued ("intangibles").
  
  
  RESULTS
  We discuss several recommendations for each key method, and we use a hypothetical example of the cost-effectiveness of a vaccine to prevent human immunodeficiency virus (HIV) to illustrate our points.
  
  
  CONCLUSIONS
  We conclude that the methods of economic evaluation may both understate and overstate the cost-effectiveness of prevention.
authors.affiliation: Department of General Internal Medicine Institute for Health Policy Studies, School of Medicine, University of California, San Francisco, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Phillips
authors.forename: D R
authors.initials: DR
authors.lastname: Hotlgrave
mesh_terms: D003362:Cost-Benefit Analysis / Q000379:methods*; D003365:Costs and Cost Analysis; D003657:Decision Making; D017048:Health Care Costs; D015276:Health Care Rationing / Q000191:economics*; D006302:Health Services Research / Q000379:methods; D006801:Humans; D017059:Models, Econometric; D011314:Preventive Health Services / Q000191:economics*; D011322:Primary Prevention; D015397:Program Evaluation / Q000379:methods; D014481:United States