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Decision aids for patients facing health treatment or screening decisions: systematic review

BMJ 1999; 319 doi: (Published 18 September 1999) Cite this as: BMJ 1999;319:731
  1. Annette M O'Connor, professor (aoconnor{at}LRI.CA)a,
  2. Alaa Rostom, gastroenterologista,
  3. Valerie Fiset, clinical nurse specialistb,
  4. Jacqueline Tetroe, research associatea,
  5. Vikki Entwistle, senior research fellowc,
  6. Hilary Llewellyn-Thomas, professord,
  7. Margaret Holmes-Rovner, professore,
  8. Michael Barry, chief, general medicine unitf,
  9. Jean Jones, consumer health advocateg
  1. a University of Ottawa School of Nursing and Faculty of Medicine, Loeb Health Research Institute Clinical Epidemiology Unit, Ottawa Hospital, Civic Campus, Ottawa, Ontario, Canada K1Y 4E9
  2. b Sisters of Charity of Ottawa Health Services, Ottawa, Ontario, Canada
  3. c Health Services Research Unit, University of Aberdeen, Aberdeen, Scotland
  4. d University of Toronto, Institute for Clinical Evaluative Sciences, North York, Ontario, Canada
  5. e Department of Medicine, Michigan State University, East Lansing MI, USA
  6. f General Medicine Unit, Massachusetts General Hospital, Boston, MA, USA
  7. g Dundas, Ontario, Canada
  1. Correspondence to: A O'Connor
  • Accepted 19 August 1999


Objective: To conduct a systematic review of randomised trials of patient decision aids in improving decision making and outcomes.

Design: We included randomised trials of interventions providing structured, detailed, and specific information on treatment or screening options and outcomes to aid decision making. Two reviewers independently screened and extracted data on several evaluation criteria. Results were pooled by using weighted mean differences and relative risks.

Results: 17 studies met the inclusion criteria. Compared with the controls, decision aids produced higher knowledge scores (weighted mean difference=19/100, 95% confidence interval 14 to 25); lower decisional conflict scores (weighted mean difference=−0.3/5, −0.4 to −0.1); more active patient participation in decision making (relative risk = 2.27, 95% confidence interval 1.3 to 4); and no differences in anxiety, satisfaction with decisions (weighted mean difference=0.6/100, −3 to 4), or satisfaction with the decision making process (2/100,−3 to 7). Decision aids had a variable effect on decisions. When complex decision aids were compared with simpler versions, they were better at reducing decisional conflict, improved knowledge marginally, but did not affect satisfaction.

Conclusions: Decision aids improve knowledge, reduce decisional conflict, and stimulate patients to be more active in decision making without increasing their anxiety. Decision aids have little effect on satisfaction and a variable effect on decisions. The effects on outcomes of decisions (persistence with choice, quality of life) remain uncertain.


  • Funding The overview was supported by a group grant from the Medical Research Council of Canada. At the time of the study AO'C was funded by the Ontario Ministry of Health, VE held a special research fellowship from the Leverhulme Trust, and HL-T was a national health scholar funded by Health Canada's National Health Research Development Program.

  • Competing interests None declared.

  • website extra A table giving details of the studies included in the review is available on the BMJ's website

  • Accepted 19 August 1999
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