title: Are methods for estimating QALYs in cost-effectiveness analyses improving?
abstract: OBJECTIVE
  The objectives of this study were to examine variations in the methods used by researchers to estimate QALYs in published cost-effectiveness analyses, and to investigate whether the methods have improved over time.
  
  
  METHODS
  Using a MEDLINE search, the authors identified 86 original cost-effectiveness analyses, published between 1975 and 1995, that used QALYs as the measure of effectiveness. For each study, they recorded the health-state classification system, the source of the preference weights, the measurement technique, and the discount rate. The methods used were compared with the recommendations of the U.S. Panel on Cost-Effectiveness in Health and Medicine.
  
  
  RESULTS
  Only 20% of the studies used "generic" health-state classification systems (e.g., health utilities index); 21% relied on community-based weights; 40% used formal measurement techniques (e.g., time-tradeoff method); and 88% discounted both future costs and QALYs. There was little evidence that methods had improved over time.
  
  
  CONCLUSIONS
  The results illustrate extensive variation in the construction of QALYs in cost-effectiveness analyses and reveal that most studies have not adhered to practices now recommended by leaders in the field. There is a need for more methodologic rigor and consistency if the results of such studies are to be compared and used for purposes of allocating resources.
authors.affiliation: Program on the Economic Evaluation of Medical Technology, Harvard School of Public Health, Boston, MA 02115, USA. pneumann@hsph.harvard.edu
authors.forename: P J
authors.initials: PJ
authors.lastname: Neumann
authors.forename: D E
authors.initials: DE
authors.lastname: Zinner
authors.forename: J C
authors.initials: JC
authors.lastname: Wright
mesh_terms: D002965:Classification; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D017048:Health Care Costs; D006801:Humans; D019057:Quality-Adjusted Life Years; D012107:Research Design