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.

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 decision-making (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?

Evidence Report/Technology Assessment

Number 46

EVIDENCE-BASED PRACTICE CENTERS

Impact of Cancer-Related Decision Aids

Summary

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES • Public Health Service

Agency for Healthcare Research and Quality • www.ahrq.gov
• 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?

Methodology

Selection Criteria and Screening Process

The authors regarded as potentially eligible any article

1) that described a study in humans; and 2) 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.

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

2
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.

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?

3
• 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.

Availability of 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. A limited

number of prepublication copies of this report are available

free of charge from the AHRQ Publications Clearinghouse

by calling 800-358-9295. Requestors should ask for

Evidence Report/Technology Assessment No. 46, Impact of

Cancer-Related Decision Aids. The final report is expected

to be available by Summer 2002 (AHRQ Publication No.

02-E004). At that time, printed copies may be obtained.

Internet users will be able to access the report online

through AHRQ’s Web site at:

www.ahrq.gov/clinic/epcix.htm

www.ahrq.gov

AHRQ Pub. No. 02-E033

July 2002

ISSN 1530-440X