Evidence brief: decision aids for people facing health
treatment or screening decisions
Key messages
For people making decisions about treatment and screening, decision aids increase
knowledge, and help people feel more informed and clearer about the outcomes that
matter most to them.

Decision aids probably help people understand the risk associated with different options
and actively contribute to making decisions about their care. Decision aids may help
people choose treatment or screening options that are consistent with their personal
values.
We are uncertain about the effects of decision aids on health and health systems
outcomes.
?
Inside
1
Purpose of this statement
2
Decision aids in health care
3
Why is it important to know about the effects of decisions aids?
4
Do decision aids improve outcomes for people facing treatment and screening decisions?
5
Summary of what is known about the effects of decision aids
6
The Cochrane Review at a glance
7
References
1. Purpose of this statement
This statement is designed to provide information based on the best evidence available at the time of
publication to assist in decision-making. The contents of this statement are based on evidence from a single
Cochrane Systematic Review. Cochrane reviews are reviews of clearly formulated questions that use
systematic and explicit methods to identify, select, and critically appraise relevant research, and to collect and
analyse data from the studies that are included in the review. Other published evidence was not considered.
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2. Decision aids in health care
Decision aids are designed to help people make well informed choices about the health care they receive. They
can be in the form of pamphlets, videos or web-based tools. They are used to help patients choose between
treatment options when there is no single best treatment or when the effects of a treatment are uncertain. They
may also be used to help people decide if they want to be screened for a condition, especially when there are
no effective treatments for the condition or when there are potential harms associated with the screening test.
Decision aids help people consider each of the available treatment or screening options and weigh up the
potential benefits, harms, and consequences for them. Effective decision aids should enable people to choose
an option that is likely to have the outcomes they value most. Decision aids should also make the decisionmaking process easier. They aim to do so by helping people understand the options and their consequences,
clarify which outcomes matter most to them, and take an active role in decision making [1].
3. Why is it important to know about the effects of decision aids?
Patients frequently face decisions about healthcare treatments and screening for which there is more than one
option and the best choice depends on personal values. Research can help us understand whether decision
aids actually help people choose healthcare options that match their personal values. We need to know whether
these aids help people feel more informed and certain about the choices they make, understand the benefits
and risks of each option, and participate in making decisions with their health practitioners. We also need to
understand what types of decision aids (pamphlets, videos, web-based tools) are most effective and what
content is needed to achieve the best outcomes.
4. Do decision aids improve outcomes for people facing treatment
and screening decisions?
A recent Cochrane systematic review evaluated published scientific evidence about the effects of the decision
aids on people facing treatment and screening decisions [1, 2]. The review found that decision aids improved
knowledge of available options and helped people make better choices about treatment and screening. The use
of decision aids that included explicit information about the risk of particular outcomes led to more people
understanding the possible benefits and harms associated with different treatment or screening options.
With decision aids, 54 out of 100 people are estimated to have an accurate understanding of the
possible benefits and harms associated with the available treatment or screening options
Without decision aids, 30 out of 100 people are estimated to have an accurate understanding of the
possible benefits and harms associated with the available treatment or screening options
Decision aids that explicitly helped people clarify their values led to more people choosing a screening or
treatment option that was likely to have the outcomes that mattered most to them (an option consistent with their
values).
With decision aids, 50 out of 100 people are estimated to choose a treatment or screening option
likely to have the outcomes they value most
Without decision aids, 32 out of 100 people are estimated choose a treatment or screening option
likely to have the outcomes they value most
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Compared to usual care, decision aids also improved the process of decision making. Decision aids helped
people feel more informed about treatment and screening options and feel clearer about which outcomes
mattered most to them. When decision aids were used, patients were more likely to take an active role in
decision-making and were less likely to remain undecided about which option to choose.
The actual screening and treatment decisions people made when using decision aids varied. The use of
decision aids reduced the number of patients choosing elective surgery and the number of patients choosing to
undergo prostate specific antigen testing for prostate cancer. Compared to simple decision aids, detailed
decision aids reduced the number of women electing to have hormone therapy for menopausal symptoms. The
effects of decision aids on choices made for other types of treatment and screening were variable.
We do not know what types of decision aids (pamphlets, videos, web-based tools) are most effective or how
much detail is needed to achieve the best outcomes.
5. Summary of what is known about the effects of decision aids
Outcome
What do we know about the effects of decision aids on this
outcome?1
Outcomes related to the quality of the
choice include whether patients:
 have knowledge of available
options;
 have an accurate understanding of
the possible benefits, risks and
consequences of each option
(accuracy of risk perception); and
 choose an option that is
consistent with their values
Decision aids increased:
 knowledge of available options (13 points higher on a scale from
0 (no knowledge) to 100 (perfect knowledge) among people using
decision aids compared to usual care, 95% confidence interval 11
to 16 points higher; 42 trials, 10,842 participants; high quality
evidence).
 accuracy of risk perception (those using decisions aids with
descriptions of outcome probabilities in numbers or words were
1.8 times more likely to have an accurate perception of risk than
those who did not receive information about outcome
probabilities, 95% confidence intervals 1.5 to 2.2 times higher; 19
trials, 5868 participants; moderate quality evidence), and
 choice of an option that was consistent with personal values
(those using decisions aids with explicit values clarification
exercises were 1.5 times more likely to choose an option that was
consistent with their values than those using decision aids
without this information, 95% confidence intervals 1.2 to 2.0
times higher; 13 trials, 4670 participants; low quality evidence).
Outcomes related to the quality of the
decision-making process include
whether patients:
 recognise that a decision needs to
be made;
 feel informed about the options
and their benefits, risks and
consequences;
 feel clear about what outcomes
matter most to them (clear
values);
 discuss goals, concerns and
preferences with their healthcare
professionals; and
 take an active role in decision
making
Compared to usual care, people using decision aids:
 felt more informed about treatment or screening options (7
points higher on a scale from 0 (least informed) to 100 (most
informed); 95% confidence intervals 5 to 10 points higher; 22
trials, 4343 participants; high quality evidence),
 felt more clear about the outcomes that mattered most to them
(6 points higher on a scale from 0 (least clear) to 100 (most clear);
95% confidence intervals 4 to 9 points higher; 18 trials, 3704
participants; high quality evidence),
 were 34% less likely to have a practitioner control the decision
making (95% confidence intervals 19% to 47% less likely; 14 trials,
3234 participants; moderate quality evidence), and
 were 41% less likely to remain undecided (95% confidence
interval 28% to 53% less likely; 18 studies, 2830 participants).
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Outcome
What do we know about the effects of decision aids on this
outcome?1
Actual choice made measures which of
the treatment or screening options
patients chose
Compared to usual care, people using decision aids:
 were 13% less likely to choose prostate specific antigen testing
for detecting prostate cancer (95% confidence intervals 2% to
23% less likely; 9 trials, 3565 participants),
 were 21% less likely to choose elective surgery over conservative
options (95% confidence intervals 7% to 32% less likely; 15 trials,
3553 participants), and
 were 27% less likely to choose hormone therapy for menopausal
symptoms when using detailed decision aids compared to simple
decision aids (95% confidence intervals 2% to 27% less likely; 3
trials, 357 participants).
Decision aids had variable effects on other choices and uncertain
effects on adherence to the chosen option.
Health outcomes include health status,
quality of life, anxiety, emotional
distress, and regret
In most studies, there was little or no difference in anxiety (30 trials),
depression (9 trials) or regret (7 trials) between those using decision
aids and those receiving usual care (results of individual trials not
pooled). The effects of decision aids on other health outcomes are
uncertain.
Healthcare system outcomes include
the costs and cost-effectiveness of
decision aids, and length of
consultation
The effect of decision aids on the length of consultation is uncertain,
with varied results across studies. The effects of decision aids on other
healthcare system outcomes are uncertain.
1
The 95% confidence interval indicates the range in which the actual effect is likely to be.
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6. The Cochrane Review at a glance
Included studies
The review included 115 randomised trials involving 34,444 people. There are 30 ongoing studies, not
yet included in the review. Participants were making screening or treatment decisions for themselves, a
child, or someone in their care. Most commonly, these decisions related to prostate cancer screening
(15 trials), surgery (13 trials), colon cancer screening (10 trials), use of hormone therapy for
menopausal symptoms (10 trials), genetic testing for breast cancer (7 trials), prenatal screening (6
trials), and medication for atrial fibrillation (3 trials). The trials were set in Australia (15 trials), Canada
(21 trials), China, Finland (2 trials), Germany (5 trials), the Netherlands (2 trials), Sweden, the United
Kingdom (14 trials), and the United States (53 trials). One trial was set in both Australia and Canada.
Interventions evaluated
Decision aids were defined as interventions designed to help people make specific and deliberative
choices between treatment or screening options. Decision aids had to include information that (1) made
the decision explicit, (2) described options and their associated outcomes, and (3) helped patients
clarify their values. Most decision aids included information on the clinical problem (91%) and the
probability of different outcomes in numbers or words (88% of aids). Less common were exercises to
clarify values (60% of aids), guidance on making and communicating decisions (63% of aids), and
examples of others’ experiences (50% of aids). Decision aids were compared to usual care or more
detailed decision aids.
Outcomes measured
The primary outcomes for this review were based on the International Patient Decision Aids Standards
criteria for evaluating decision aids. The criteria assess the quality of the choice made and the quality
of the decision-making process. Outcomes related to the quality of the choice include knowledge of
available options, accuracy of risk perception (understanding possible benefits and harms of each
option), and choosing an option consistent with personal values. Outcomes related to the quality of the
decision-making process include recognition that a decision needs to be made, feeling informed about
options and their consequences, feeling clear about personal values (what outcomes matter most),
discussing values with their practitioner, and being involved in decision making. Other outcomes
related to the process included patient-practitioner communication, proportion of people who remain
undecided, and satisfaction with the process and decision.
Quality of the evidence
The evidence contributing to this review varied in quality from high to low. For findings based on high
quality evidence, further research is very unlikely to change our confidence in the estimate of effect.
For findings based on low quality evidence, further research is very likely to have an important impact
on our confidence in the estimate of effect and is likely to change the estimate.
Key dates
Review published January 2014
Review content assessed as up-to-date June 2012
7. References
1.
2.
Stacey, D., et al., Decision aids for people facing health treatment or screening decisions. Cochrane Database Syst
Rev, 2014. 1: p. CD001431.
Plain language summary of Cochrane Systematic Review: Decision aids for people facing health treatment or
screening decisions. 2014; CD001431]. Available from: http://summaries.cochrane.org/CD001431/decision-aids-tohelp-people-who-are-facing-health-treatment-or-screening-decisions.
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