title: On what basis should the effectiveness of decision aids be judged?
abstract: OBJECTIVE
  Attempts to synthesize the evidence on the effects of decision aids have been hampered by the lack of consensus regarding how such effectiveness should be measured. This paper seeks to describe and critically assess the range of measures of effectiveness used in randomized controlled trials of decision aids.
  
  
  METHODS
  The published systematic reviews of the field were used to identify primary studies evaluating the effects of decision aids.
  
  
  METHODS
  Non-randomized trials were excluded from this review. As were abstracts and theses of subsequently published studies, methodological papers and reports of subgroups of a study's main publication.
  
  
  RESULTS
  A wide range of measures were used to evaluate the effectiveness of decision aids. The most commonly used measures sought to assess treatment decisions, patient's knowledge and the decision-making process. This pattern was repeated when primary measures of effectiveness were examined. No study attempted to measure the extent to which decisions made were consistent with patient's values.
  
  
  CONCLUSIONS
  Within the current literature there is little consensus on what the aims of decision aids should be. If we can agree that the aim of a decision aid is to help patients make specific personal treatment choices, then evaluations of decision aids should measure the primary effectiveness of their interventions in terms of the extent to which they enable patient's to undergo treatments that agree with their values.
authors.affiliation: Health Economics Research Group, Brunel University, Uxbridge, Middlesex, UK. hesradk@brunel.ac.uk
authors.forename: Andrew D M
authors.initials: AD
authors.lastname: Kennedy
mesh_terms: D003657:Decision Making; D003661:Decision Support Techniques; D006302:Health Services Research; D006801:Humans; D017063:Outcome Assessment, Health Care; D010358:Patient Participation; D010817:Physician-Patient Relations; D016032:Randomized Controlled Trials as Topic; D006113:United Kingdom