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Patient decision aids: tools to enhance quality of healthcare decisions

Dawn Stacey
Assistant Professor
School of Nursing
University of Ottawa

Carol Bennett
Ottawa Health Research Institute

Annette O’Connor
Tier 1 Canada Research Chair in Health Care Consumer Decision Support
Professor and Senior Scientist University of Ottawa and Ottawa Health Research Institute

Patient decision aids (PtDAs) may be able to assist policymakers in setting benchmarks for over-use of “grey zone” treatments. Grey zone treatment decisions are those that rely on the patient’s judgement of the benefits and harms of a treatment in the absence of adequate scientific evidence clearly supporting either harmful or beneficial effects.

The goal of evidence-based medicine is to reduce the overuse of black zone, or harmful, treatments and underuse of white zone, or effective, treatments through professional and patient education, organisational changes and funding incentives.(1,2) While it is more difficult to judge the over- or under-use of grey zone treatment options, we do know that the rate of uptake of these options varies greatly. In contrast to white zone procedures, such as surgery for hip fractures or colon cancer, that have little regional variation, the uptake of grey zone surgical options, such as hip replacement or prostate cancer surgery, can vary two- to fivefold.(2-4) Furthermore, grey zone decisions create higher decisional conflict – defined as psychological uncertainty. Unresolved decisional conflict leads to decisional delay or reversal, dissatisfaction, regret and blaming the practitioner for poor outcomes.(5,6)

In 2005, the International Patient Decision Aid Standard Collaboration (IPDAS) reached a benchmark for grey zone decisions: when clinicians judge that patients are eligible for grey zone treatments, their uptake should be consistent with informed patients’ values. However, how can one obtain informed patient values? Evidence-based PtDAs have been developed as an adjunct to consultation to prepare people to participate in decision-making.(7,8) PtDAs are interventions designed to help patients discuss treatment options with their clinicians and make specific, deliberative choices.(8) The aim of a PtDA is to improve decision quality and to reduce unwarranted practice variation by:

  • Providing facts about the condition, options, outcomes, and probabilities.
  • Clarifying patients’ values (ie, the outcomes that matter most to them).
  • Guiding patients in the steps of deliberation and communication so that a choice can be made that matches their informed values.

Effectiveness of PtDAs

Decision quality
When PtDAs are used as adjuncts to practitioner counselling, they have consistently demonstrated superior effects relative to usual practices on the following indicators of decision quality: increased knowledge scores; improvement in the proportion of patients with realistic perception of the chances of benefits and harms; lowered scores for decision conflict related to feeling uninformed; and reduced proportions of patients who are passive in decision making. These improvements in decision quality have been shown to be accomplished without deleterious effects on patient satisfaction, patient anxiety, or practitioner consultation time.

Decision-making process
Compared with standard care, PtDAs have been shown to significantly reduce decisional conflict, the proportion of patients remaining undecided and practitioner controlled decision-making. Complex PtDAs have been shown to have an advantage over simpler PtDAs in ensuring patient values match the decision. In general, patient satisfaction with decision-making is high for both those who receive standard care and those who use PtDAs.

Patient health outcomes
There is no consistent evidence to indicate that PtDAs are superior to standard care with respect to patient health outcomes. However, as discussed earlier, PtDAs are used for grey zone decisions with benefit/harm ratios that patients value differently. Therefore, the best choice for the patient is one that is less likely to result in harm/side effects the patient wants to avoid.

Uptake rates for different options
Exposure to PtDAs has been shown to reduce, by 24%, the uptake of more invasive surgical options in favour of more conservative surgical or medical options, without adverse effects on health outcomes.(8,9) PtDAs have also been shown to reduce uptake of medications such as hormones for menopause and warfarin for atrial fibrillation. PtDAs have had more variable effect on the uptake of other treatment options (eg, hepatitis B vaccination, chemotherapy for breast cancer, circumcision of male newborns, high blood pressure treatment and minor dental surgery). There is insufficient evidence on the effect of PtDAs on adherence to chosen options.

Strength of the evidence
The evidence summarised above is based on 29 randomised controlled trials that were identified using systematic review methods. The source of evidence included the 2003 Cochrane systematic review of randomised trials that were published between 1966 and August 2002, and a more recent update of the Cochrane systematic review that included trials published as late as August 2004.(8,9) Randomised controlled trials and systematic reviews can provide the strongest levels of evidence. The main limitations of the included trials were that none of the patients or practitioners could be blinded to the intervention and several trials had too small a sample size to detect significant differences between the groups.

Implications for practice and policy
There has been a shift, over the last few decades, from a paternalistic model of decision-making to a shared or consumerist model, in which patients are active participants in their care.(10-13) The majority of patients in many countries want to take an active role in making their risk-related (“close-call”) health decisions.(14) Studies show that clinicians are poor judges of patients’ values and patients often have unrealistic expectations of treatment benefits and harms. Therefore, two types of experts are needed to judge grey zone decisions: clinicians for providing technical information on options, outcomes and probabilities; and patients to judge the value of good and bad outcomes. PtDAs are designed to enhance this interaction rather than replace it. Based on a systematic review of evidence, patients facing grey zone decisions and their practitioners need help beyond standard counselling. Decision aids improve the quality of patient decision-making, facilitate the integration of patient values into evidence-based medical practice and enhance the practitioner–patient interaction. The challenge is in developing best practices for implementing PtDAs as part of a process of care that will lead to better evidence-based decision-making that matches patients’ values.

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The quality of decisions for grey zone treatment options is inadequate and is likely leading to the overuse of treatments that informed patients do not value. PtDAs support patients in making evidence informed choices that could assist policymakers in setting benchmarks for the overuse of grey zone treatments, thereby freeing resources to promote more effective treatment. Moreover, in setting policies regarding waiting lists for radiation treatment, planners and policymakers should take into account decision quality benchmarks in addition to time-to-treatment benchmarks. The potential shifting of choices could also affect facilities planning; for example, the increasing need for surgical suites may be less compelling than the need for radiation facilities if informed patient choice is obtained through use of PtDAs.

It is important that universally accepted quality standards for the development and evaluation of PtDAs are adopted. Furthermore, there is a need to develop services models for their use, including training practitioners to develop skills in shared decision-making.

Implementing PtDAs as part of the process of care
Three essential strategies have been proposed for the successful implementation of PtDAs as part of the process of care:(15)

  • Practitioner training: to develop skills in shared decision making and using PtDAs (most practitioners focus on fact-giving with little attention to the influence of values or others’ opinions on the process of decision-making). (16-19)
  • Improving access to a comprehensive library of PtDAs (see for a listing of 500 patient decision aids).
  • Models to provide patient decision support. Current models include: patient resource libraries (on site or virtual such as NHS Direct in the UK); nurse call centres funded by health plans (eg, Health Dialog, Boston, US); shared decision-making centres linked to practices (eg, Dartmouth Hitchcock Medical Center, Lebanon, US); and fully integrated practice models in which PtDAs and coaching are integrated into care pathways (eg, UK NHS Urology Service Demonstration project).

Research on a selection of PtDAs showed that these evidence-based tools significantly improved the quality of patients’ decision making when the choice of treatments was difficult and depended on individuals’ values relating to benefits and harm. As there are now over 500 PtDAs, it is essential that quality standards be adopted for their development and evaluation. Furthermore, there is a need to develop large-scale implementation projects to fully evaluate service delivery models in diverse populations.



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  16. Stacey D, Graham ID, O’Connor AM, Pomey M. Worldviews on Evidence-Based Nursing 2005; 2:184-95.
  17. Elwyn G, Charles C. Shared decision making: The principles and the competences. In: Edwards A, Elwyn G, editors. Evidence-based patient choice: inevitable or impossible? Oxford: Oxford University Press; 2001. p. 18-43.
  18. Guimond P, Bunn H, O’Connor AM, et al. Patient Educ Couns 2003;50:235-45.
  19. Towle A,Godolphin W. Education and training of health care professionals. In: Edwards A, Elwyn G, eds. Evidence-based patient choice: inevitable or impossible? Oxford: Oxford University Press, 2001. p. 245-69.

International Patient Decision Aids Standards Collaboration
British Medical Journal
Clinical evidence for patients