Title: A systematic review of assessment instruments used in studies on
shared decision making
Author / Co-authors: Noriko Inukai1), Takeo
Nakayama2)
Affiliation: 1) Moff, Inc., 2) Kyoto University Graduate School of
Medicine, School of Public Health
3-3-6 Minami Aoyama, Mintato-ku, Tokyo 107-0062
Key words: decision making, assessment, patient-centered
1. Introduction
Shared decision making (SDM) is a model of communication processes that
facilitate cooperative decision making between a patient and medical
practitioner regarding treatment.1,2 Towle and
Godolphin3 systematically classified processes
involved in SDM as a series of events; their model starts with
partnership building between a patient and medical practitioner,
followed by subsequent steps that include information provision on the
part of the medical practitioner and confirmation of whether the
information is appropriately transmitted to the patient, ultimately
leading to cooperative decision-making with appropriate follow-up. Each
of these processes is meaningful and should be implemented accordingly,
as the effectiveness of SDM has been demonstrated in a number of
studies.4-9
The use of assessment instruments is an important way to gain insight
into the practice of SDM. Simon10 and
Scholl11 investigated a variety of instruments used
for the purpose of measuring SDM and identified 19 different
instruments. They reported on the methods of measurement employed in
each instrument, the purpose of their development, and the reliability
and validity of each instrument. However, the instruments currently used
to measure SDM are unclear, as are the aspects of SDM processes each
instrument reflects. In order to fully utilize the various assessment
tools available for use, it is important to not only reveal what
instruments are used to measure SDM but also shed light on which aspects
of SDM are taken by different instruments. If such an understanding
could be gained (i.e., aspects of the SDM communication process model
each instrument captures), then it would be possible to select an
appropriate assessment instrument according to the specific purpose in
various clinical settings. The use of assessment instruments may allow
for visualization of the practice of SDM, which in turn will help
determine optimal communication processes for patients and medical
practitioners.
In this study, we reviewed assessment instruments used in studies on SDM
with the aim of clarifying what aspects of SDM processes each instrument
is intended to capture.
2. Methods
This review was conducted according to the Preferred Reporting Items for
Systematic Review and Meta-Analysis (PRISMA)
statement.12
2-1. Information sources
The following databases were used: MEDLINE PubMed (1950 -
present),Cochrane database (1992 - present), Web of Science (1990 -
present), Physiotherapy Evidence Database (PEDro; 1999 - present),
Occupational Therapy Systematic Evaluation of Evidence (OT seeker; 2003
- present), Cumulative Index to Nursing and Allied Health Literature
(CINAHL; 1981 - present), and Ichushi-Web (Ichushi; 1977 - present).
Database searches were conducted on March 31, 2016.
2-2. Search term
In order to extract articles of which the main theme was SDM, searches
were conducted for titles that included the search term, “shared
decision making.” This search term was decided through brainstorming
among three medical caregivers (physician, physical therapist, and
occupational therapist).
2-3. Selection criteria for articles
Among articles obtained from the databases, target articles were
selected according to the following inclusion criteria: 1) full text is
available; 2) written in either English or Japanese; 3) original paper
(excluding reviews, review articles, case reports, letters, conference
minutes, and commentaries); and 4) published in 1997 and thereafter,
i.e., after the definition of SDM was established. Exclusion criteria
were 1) no description is provided regarding the instrument used; 2) the
instrument used is difficult to obtain; 3) had a unique design (e.g.,
review article); and 4) the instrument used was originally developed,
5)the studies that targeted students and medical practitioners such as
therapists were excluded from the total count of articles.
2-4. Data collection and analysis
Selected articles were summarized in a table and reviewed individually
by 2 evaluators (NK, SF). Contents reviewed included author, journal,
and year of publication. Instruments used to assess the practice of SDM
were extracted, and the number of articles in which these instruments
were used, and the target of each instrument (respondents), were
recorded.
In order to understand what aspects of SDM each instrument captured,
content analysis was performed to examine whether questionnaire items of
each instrument contained descriptions pertaining to 9 SDM steps (Table
1).13 There are several concepts that define SDM,
e.g., 4 elements proposed by Charles et al.,1 7
elements proposed by Towle et al.,3 and 8 elements
proposed by Elwyn et al14, and 9 SDM steps proposed by
Kriston L et al.13 Among these, we used the 9 steps
that are considered most comprehensive. When opinions differed between
the evaluators, discussions were repeated until a consensus was reached;
if no consensus was reached, a final decision was made through
discussions with a 3rd member.
We also analyzed the extracted instruments in terms of targeted
diseases. In order to examine what disease area the instrument in each
article was used in, we classified the articles based on descriptions
within the articles. If there was no clear description of disease name
(e.g.,), we excluded the article from the count for the number of
diseases when the patient’s disease is unknown, and so on.
3. Results
In total, 1,346 articles were extracted from the database searches. Of
these, 659 met the inclusion criteria. After applying the exclusion
criteria, a total of 115 articles were eligible for analysis (Figure 1).
Among these, 16 assessment instruments (scales) were identified (Figure
1).
Among the extracted articles, the most frequently used instrument was
the Observing Patient Involvement in Decision Making (OPTION)
scale2 (42 studies), followed by the 9-item Shared
Decision-Making Questionnaire (SDM-Q-9)13 (20
studies), the Decisional Conflict Scale (DCS)15 (16
studies), and the Control Preference Scale (CPS)16 (10
studies). Fourteen of the 16 instruments are designed to be responded to
by patients alone. The OPTION scale uses a sound recording of scenes of
decision-making to obtain responses from a third party. The Shared
Decision Making Questionnaire-physician version
(SDM-Q-Doc)18 uses responses of only medical
practitioners.
Table 2 shows the results of assessment of SDM processes for each
instrument. Among the extracted instruments, proportions of instruments
with questionnaire items pertaining to each step of the SDM process are
shown in Table 3. Of the 9 SDM steps, the most frequently included in
the questionnaire items were Step 4 (“informing on the benefits and
risks of the options”) and Step 5 (“investigation of the patient’s
understanding and expectations”) (81.3%). Step 6 (“identification of
both partners’ preferences”) and Step 7 (“negotiation”) were the
second most frequently included steps (68.8%), followed by Step 3
(“presentation of treatment options”) (56.3%). SDM-Q-9 covered 8 of
the 9 steps, except for Step 9 (“arrangement for follow-up”). None of
the instruments covered all 9 steps.
Table 4 shows disease areas in which the extracted instruments were
used. Cancer was the most common disease area. In particular, SDM
appeared to be prevalent in patients with breast cancer. Mental
disorders represented the second most common disease area, followed by
musculoskeletal disorders.
4. Discussion
In this study, we conducted a systematic literature review to extract
assessment instruments concerning SDM in order to examine which aspects
of SDM these instruments were intended to capture. Our review yielded 15
instruments, each of which was found to reflect different aspects of
SDM.
Ten of the 15 instruments related to SDM matched those previously
reported by Simon et al.10 and Scholl et
al.11 The remaining 5 instruments were newly extracted
in the present study and included SDM-Q-Doc,18Decisional Regret Scale,26 CollaboRATE
score,25 MAPPIN’SDM,24 and
Man-Son-Hang scale.28 Three of these (SDM-Q-Doc,
CollaboRATE score, and MAPPIN’SDM) were developed after Scholl et al.
published their review in 2011. With regard to the Decisional Regret
Scale and Man-Son-Hang scale, which were developed prior to 2011 and had
been used to measure regret and satisfaction at the time of
decision-making, it might not have been included in the paper on the
subject of “shared decision making” that was the subject of this
review since they are intended to measure the results of decision-making
rather than assess decision-making processes.
With respect to the 9 steps of SDM subjected to assessment, Step 4
(“information on the benefits and risks of the options”) and Step 5
(“investigation of the patient’s understanding and expectations) (12
instruments; 80%) were the most frequently included in the extracted
instruments, followed by Step 6 (“identification of both partners’
preferences”) and Step 7 (“negotiation”) (10 instruments; 66.7%).
Kaiser et al.30 and Samson et al.31reported that, when decisions are made between a physician and patient,
it is important for the physician to provide information pertaining to
both risks and benefits of treatment so that the patient shares that
understanding. As requirements for SDM, Elwyn et al.32and Stacey et al.33 noted the importance of making
decisions while taking into consideration patient preferences, as well
as risks, benefits, and uncertainty regarding treatment. The proportion
of instruments that included items pertaining to Steps 1, 2, 8, and 9
were low. The reason for this may be that, while the steps are important
elements when preparing for SDM and/or reflecting on the processes
involved, some aspects of these elements are difficult to grasp. Thus,
it is likely that these steps were not extracted as items of the
instruments. On the other hand, the US Preventive Services Task
Force34 states that patients should understand their
disease (seriousness of symptoms) and risks to be avoided, as well as
the risks and benefits of treatment options and the uncertainty of
alternatives, and contemplate what medical recipients value in decision
making. In the present study, although the proportion of instruments
that focused on presupposed elements or post-decisional factors of SDM
(i.e., Steps 1, 2, 8, and 9) was low, those steps are considered
important in light of the fact that going through a process of
communication is the essential part of SDM.
Among the 16 instruments examined in this study, SDM-Q-9 included most
steps; however, none of the instruments covered all 9 steps. One
possible reason for this is that there are separate instruments for
evaluating SDM processes and outcomes. The API, Decisional Registry
Scale, and the Man-Son-Hang scale were originally developed to measure
the outcomes of SDM, i.e., what changes are brought about as a result of
practicing SDM. Thus, these instruments are not intended to evaluate the
processes of SDM. Therefore, it is understandable that the extracted
instruments did not cover all 9 steps. As our findings suggest,
instruments for evaluating SDM differ in what they measure according to
the purpose for which they were created,35 and thus,
it is necessary to select one that suits the objective of the
evaluation. When selecting an instrument to assess SDM, we should first
determine whether the subject of interest is the process or outcome of
SDM; for the former, there is a need to clarify which one of the 9 steps
is of particular focus. This would then allow for selection of the
appropriate assessment instrument for the SDM process of interest.
The analysis of disease areas for which the extracted instruments were
used revealed cancer and mental disorders to be most common. According
to Whitney et al.,36 SDM is best suited for cases in
which treatment results are highly uncertain (i.e., multiple options are
available); cancer and mental disorders represent such areas. On the
other hand, the role of SDM in areas with relatively high evidence
reliability (i.e., there is one particular treatment that is expected to
yield favorable outcomes) is smaller. In such areas, the communication
style likely adopted by medical practitioners is informed consent. In
the future, assessment instruments for SDM will likely be used primarily
in areas in which there is considerable uncertainty about evidence, and
where multiple options exist.
This study has several limitations. First, the present study was
conducted using only literature databases that were available on the
Internet. However, as we used 6 databases, the risk of missing important
articles is likely to be small. Second, the articles assessed in this
study included those pertaining to the development of assessment
instruments; however, with regard to those, we did not examine what
treatment scenes might be appropriate. Third, literature searches were
conducted in March 2016. Since previous reviews targeted articles
published up to 2011, our review is meaningful in that it provides
updated information. Nonetheless, further updates using information from
more recent literature are warranted.
Conclusion
We identified 16 assessment instruments used in 115 articles concerning
SDM as the main theme. The most commonly used instrument was the OPTION
scale, followed by SDM-Q-9. Step 4 (“informing on the benefits and
risks of the options”) was covered by most instruments, followed by
Step 5 (“investigation of the patient’s understanding and
expectations”). Cancer and mental disorders represented areas in which
these instruments were most frequently used.
Table 1.Process model of shared decision making