Evidence Report/Technology Assessment: Number 46
Impact of Cancer-Related Decision Aids
Summary
Under its Evidence-based Practice Program, the Agency for Healthcare Research and Quality (AHRQ) is developing scientific information for other agencies and organizations on which to base clinical guidelines, performance measures, and other quality improvement tools. Contractor institutions review all relevant scientific literature on assigned clinical care topics and produce evidence reports and technology assessments, conduct research on methodologies and the effectiveness of their implementation, and participate in technical assistance activities.
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Overview / Reporting the Evidence / Methodology / Findings / Future Research / Availability of the Full Report
Overview
Decision aids are mechanisms or
interventions that have been developed to
improve communication between health
professionals and patients, and to help
involve patients in making decisions
regarding their health care. Decision aids can
include brochures, videotapes or interactive
computer programs. Recent reviews have
suggested that decision aids may be effective
in supporting general health care decisions.
Cancer screening or treatment have been
found to be particularly prone to difficulties
in communication and decisionmaking
between health professionals and their
patients. There are a number of reasons for
these problems, including difficulties in
communicating information about poor
prognoses and the modest benefits of the
treatments used. The objective of this study
was to conduct a comprehensive, systematic
review of the literature to determine the
impact of decision aids on cancer prevention,
screening, and treatment decisions.
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Reporting the Evidence
A set of questions was initially proposed
by the National Cancer Institute's Division of
Cancer Control and Population Sciences, and
was further refined with input from members
of the McMaster University Evidence-based
Practice Center (MU-EPC) and the project
officer at the Agency for Healthcare Research
and Quality (AHRQ), which funds the EPC
program.
The Technical Expert Panel (TEP) for this
project included individuals who represented
providers of health care, experts in study
methodology, and researchers. After
consultation with the TEP, the following key
questions were selected as the focus of the
Evidence Report.
Types of Decision Aids
- What models of decisionmaking (e.g.,
informed, shared) underpin decision aids
that have been used?
- What clinical contexts (e.g., prevention,
screening, and treatment) have been
investigated?
- What has been the clinical focus of the
decision aids (e.g., type of cancer and
extent of disease)?
- What has been the mode of delivery (e.g.,
print, interactive video)?
Populations Using Decision Aids
- On what populations has the research
been conducted?
- Have decision aids been developed for or
used by members of special populations
(e.g., elderly, ethnic groups, and low level
of education)?
Decision Aids and Outcomes
- What outcomes have been evaluated (e.g.,
increase in knowledge, satisfaction, and
behaviors)?
- Are there any key outcomes that are
associated with specific characteristics of
decision aids?
Effectiveness of Decision Aids
- What is the effectiveness of decision aids?
- What is the effectiveness of decision aids
in different clinical contexts?
- What is the effectiveness of different modes of delivery?
- What is the effectiveness of decision aids on special
populations?
Future Directions
- What specific direction is needed in future research on
cancer-related decision aids?
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Methodology
Selection Criteria and Screening Process
The authors regarded as potentially eligible any article:
- That described a study in humans.
- That was about the development or evaluation of a cancer-related decision
aid.
There was no exclusion based on study design or
language of publication. Primary studies about prevention,
screening, and treatment decisionmaking; that focused on
cancer; and that met the definition of a decision aid were
included. A decision aid was defined as "an intervention
designed primarily to help patients (or patients and clinicians
together) with making cancer-related health care decisions,
when options are available for prevention, screening, and
treatment. At a minimum, it should target some component of
decisionmaking (e.g., information exchange or involvement in
the decision process)."
Studies of benign prostatic hyperplasia, hormone
replacement therapy, and smoking cessation were excluded
as were studies published in abstract form only.
The research team used a two-stage screening process. In
the first step, six raters worked in pairs to screen the titles
and abstracts identified by the searches. In the second step,
randomly assigned pairs of raters screened full text articles,
then three reviewers checked all included studies and
categorized them according to the context of the decision
and type of study. Discrepancies were resolved by
discussion.
Literature Search
Citations of potentially relevant studies were identified
through a systematic research of: MEDLINE® from 1977 to
the end of April 2001; HealthSTAR, CANCERLIT®,
CINAHL®, Sociological Abstracts, PsycINFO, from 1977 to
August 2000; EMBASE (from 1995 to August 2000); The
Cochrane Library (issue 3, 2000); reference lists of included
studies; and, the personal files of research team members.
The development and refinement of the search strategy
followed an iterative process using the MEDLINE®
database. The refined MEDLINE® strategy was modified to
meet the specific features of the other electronic databases.
Data Extraction
In consultation with the TEP and project officer, all data
extraction forms were developed, pilot-tested, and revised
by members of the local research team. Two reviewers
completed data extraction independently for all studies.
Any disagreements were resolved by consensus. Following
consensus on each item, the data forms were scanned into a
Microsoft Access database using Teleform software.
Data Synthesis
Descriptive statistics were calculated for all fields of the
database. Evidence tables were constructed to describe the
most salient features of the included studies according to
the review questions. The local research team at the MUEPC,
in consultation with members of the partner
organizations and the project officer, evaluated the overall
quantity and quality of the data available. A draft of the
report was sent to an international Peer Review panel,
comprised of researchers in the field of decisionmaking,
experts in study methodology, and consumers. This report
incorporates many of the suggestions of the Peer Review
panel and represents a detailed qualitative synthesis of the
existing evidence, emphasizing the directions that future
researchers could take to fill knowledge gaps.
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Findings
The analysis of the yield of the literature and the general
characteristics of the studies showed that:
- A total of 1,056 full text articles were retrieved and
screened. After a preliminary screening process, 207
articles met the inclusion criteria. Of the 207 articles,
there were 168 unique studies with 39 reported in more
than one publication. After the final screening process,
61 studies that focused on either the development or
effectiveness of a cancer-related decision aid were
included and form the basis of the Evidence Report.
- Sixty-seven percent of studies were published between
1996 and 2001.
- Ninety-seven percent of studies were published in
English.
- The setting for 74 percent of studies was North America.
- Overall, 18 studies were randomized controlled trials
(RCTs), five were non-randomized controlled trials, and
the remaining studies had a mix of designs.
- Overall, the studies had low methodological quality
scores.
- Twenty-two studies examined the development process
of decision aids. In general, all studies had the same
phases: testing of content and construct validity followed
by the assessment of reliability in non-cancer
participants. There were three studies of prevention or
screening decisions and 19 of treatment decisions. There
were 14 studies involving breast cancer patients; two
each of prostate, ovarian, and lung cancer patients; and
one study each of colon cancer and leukemia patients.
Only two developmental studies focussed on special
populations (Mexican-American women, and
impoverished African-American women).
- The effectiveness of a decision aid was assessed in 39
studies: 16 RCTs, four non-randomized studies, two
non-concurrent controlled studies, six pre-post designs,
and 11 case series. Various decision aids or a
combination of strategies were used: brochures,
audiotapes, videotapes, interactive computer programs,
educational scripts, decision boards, counseling, and
informal decision analysis. Breast (23) and prostate
cancer (11) were the most frequent type of cancer
included.
- Of the 39 studies that evaluated a decision aid in a
clinical context, the ethnicity of participants was
reported in 11 studies. In 10 studies, the majority of
participants were Caucasian. Only one study evaluated
the effect of a decision aid in a special population.
- Across the studies, patients' decisions, knowledge,
anxiety, depression, satisfaction, and acceptability of the
decision aids were the most frequent outcome measures
evaluated.
- Overall, among RCTs, the decision aids appeared to
increase knowledge, and patient involvement in
decisionmaking. Anxiety and depression scores did not
appear to be increased. In patients making prostate
cancer screening decisions, significantly fewer men
decided to proceed with screening after receiving a
decision aid.
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Future Research
Our results support the proposal that decision aids are
helpful for a number of cancer screening decisions. In these
situations, such instruments can increase knowledge, do
not increase anxiety, and can influence the decision made.
In contrast, there is little data available evaluating aids for
decisions related to cancer treatment. Unfortunately,
further evidence is still needed before making specific
conclusions regarding decision aids in this situation.
The early stage of development of this field and the gaps
in our knowledge outlined in this systematic review
underline the need for further research. A number of
different areas were identified. Future research efforts
should:
- Develop a better understanding of how and when
decisionmaking occurs in the real world, who is involved
(clinician, patient, or others) and the extent of their
involvement. Further work is needed to identify the
processes involved and when they occur. Presumably,
information transfer is the first step, but what are the
stages of deliberation and how do patients and clinicians
interact at this stage? How do they ultimately make a
decision?
- Determine the key features of quality decisionmaking
from patients and clinicians. Such information will have
a number of important benefits to help investigators
develop instruments to facilitate quality decisionmaking
and perhaps, most importantly, to identify, prioritize,
and measure outcomes of effectiveness.
- Determine patients' understanding of numerical
estimates of risk. Are such numbers meaningful for
them? What is the impact of providing risk estimates on
real-life decisions?
- Determine whether decision aids are effective for cancerrelated
treatment decisions. Research in other disease
sites besides breast and prostate cancer and for metastatic
disease is also necessary. The latter may be particularly
challenging in terms of explicit discussion of benefits and
risks of proposed treatments.
- Focus on which components of a decision aid are
necessary and effective—e.g., besides exchanging
information, is counseling helpful? How should it be
instituted? Are different types of decision aids more
effective then others?
- Investigate whether decisionmaking regarding cancer is
really different from decisionmaking in other chronic
medical illnesses. In view of the life-threatening nature of
this disease, are special approaches necessary here—e.g.,
psychosocial support techniques, patient support groups,
teleconferences, or use of repetition?
- Determine what patient, clinician, or decisionmaking
factors influence the effectiveness of decision aids. Are
decision aids more or less useful in particular situations,
i.e., do decision aids facilitate communication for
clinicians who are less likely to spend time talking with
their patients? Or, alternatively, do decision aids impede
communication in a more interactive clinician-patient
relationship? Are there particular groups of patients that
benefit from decision aids? Who are they—e.g., patients
having difficulty making a decision? Can they be
identified a priori?
- Establish whether decision aids are useful for members of
special populations, e.g., the elderly, ethnic groups, or
people with a low level of education. Should decision aids
be modified for these populations and how should this be
done?
In addition to focusing on these areas our future efforts
should consider:
- Multi-center collaboration to formally set a research
agenda. From our review, there appeared to be poor
integration of different research efforts in the field.
National or international collaboration would permit
development of consensus about important basic concepts
regarding decisionmaking, what is a decision aid, and
important outcomes.
- Development of accepted conceptual framework for
decisionmaking, standardized definitions of a decision aid
and a core set of outcomes would have important benefits
for patients, clinicians, and policy makers. Outcomes
should be important to all parties and could include
patient and clinician: knowledge, satisfaction, comfort
with decisionmaking, involvement in decisionmaking,
and resources utilized for decisionmaking, and the
treatment chosen.
- With respect to evaluation, larger studies with more
rigorous design, more comprehensive reports, and studies
with longer-term followup are needed to clearly establish
effectiveness and adverse effects (if any) of decision aids,
especially for cancer-related treatment decisions. Ideal
studies would include evaluation of instruments
developed based on sound principles compared to usual
practice, with random allocation of intervention. Cluster
randomization may be necessary so that the control group
does not inadvertently receive the intervention.
Appropriate outcomes should be assessed using survey
instruments soon after administration of the intervention
and with long followup to determine any latent effects.
Studies should have sufficient statistical power to detect
important differences and to look at factors predictive of
effect. Multi-center collaboration is likely to facilitate this
process and may have additional benefits in terms of
increasing opportunities for dissemination of research
results.
- Other collaborative efforts, such as workshops and the
development of practice guidelines by policymakers,
clinicians, and patients to improve the dissemination and
implementation of decision aids should be instituted.
- More involvement of consumer groups in helping to set
the agenda, advocate for funding, facilitate the
development of studies, and disseminate results should be
considered.
The report concludes that funding should be sought from
government and industry sources to support this research.
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Availability of the Full Report
The full evidence report from which this summary was
derived was prepared for the Agency for Healthcare Research
and Quality by the McMaster University Evidence-based
Practice Center under contract No. 290-97-0017. Print copies of this report are available
free of charge from the AHRQ Publications Clearinghouse
by calling 1-800-358-9295. Requestors should ask for
Evidence Report/Technology Assessment No. 46, Impact of
Cancer-Related Decision Aids (AHRQ Publication No.
02-E004).
The Evidence Report is also online at www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat1.chapter.66534 or can be downloaded as a zipped file at www.ahrq.gov/clinic/evrptfiles.htm#canceraids.
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AHRQ Publication Number 02-E033
Current as of July 2002
Internet Citation:
Impact of Cancer-Related Decision Aids. Summary, Evidence Report/Technology Assessment: Number 46. AHRQ Publication No. 02-E033, July 2002. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/clinic/epcsums/caaidsum.htm
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