Study design
The data obtained after conducting workshops to learn SDM support, held by a government agency in Aichi Prefecture, Japan, was used in this study. In the workshops, the novel SDM measures for HCPs other than physicians that we had developed in advance were used. The collected anonymized data was converted by a person in charge of information processing, who was not involved in the study, from the descriptive data of the “Care SDM-Questionnaire for care receivers (SDM-C-patient),” “Care SDM-Questionnaire for care providers (SDM-C-provider),” and “Japanese version SDM-Q-9/Japanese version SDM-Q-Doc” to electronic data. These data were used for analyses.
SDM measures
The SDM-C-patient and SDM-C-provider were prepared based on the previously tested and published Japanese versions of the 9-item Shared Decision Making Questionnaire for patients (SDM-Q-9) [19] and physicians (SDM-Q-Doc) [20]. The original SDM-Q-9 (for patients) [10] and the SDM-Q-Doc (for physicians) [11] were developed in Germany (LK, MH, IS); the measures assess the subjectively experienced level of SDM from the patient’s and physician’s perspectives, respectively. The measures are based on a multicomponent model [21] constructed from the following four important elements of SDM [22]: (1) at least a patient and a professional participate; (2) information is shared by both parties [the patient and professional(s)]; (3) both parties [the patient and professional(s)] are aware of the availability and details of options; and (4) both parties [the patient and professional(s)] share decision making criteria and agree on the decision.
At the beginning of the questionnaire, there is a column to describe the purpose of the discussion and the content of the decision. The items are rated on a six-point Likert scale from “completely disagree” (0 points) to “completely agree” (5 points). The highest possible total score is 45 points. A higher score indicates a higher level of perceived SDM.
Adaptation of the instrument in advance
After permission was obtained from the development team of the original SDM-Q-9 and SDM-Q-Doc, the team adapted the Japanese SDM-Q-9 and SDM-Q-Doc to care SDM measures using terms that were commonly understood by HCPs in Japan, considering the different terminologies between medical and long-term care, such as notations of “Kanja” (patient) or “Riyousha” (care receiver) in Japanese. The face validity of care SDM measures was tested with the help of the care provider managers in Japan. The Japanese authors created a tentative plan and revised it to ensure the validity and comprehension of the expression after receiving opinions from the nursing manager, therapist manager, and chief care manager of the Japanese native speaker who is also a researcher. Next, a researcher who has experience working as a care provider in an English-speaking country translated it from Japanese to English. Thereafter, the care SDM measures were translated to English and revised several times based on the advice received from the development team of the original SDM-Q-9 and SDM-Q-Doc (IS, LK, MH). Thus, the final Japanese versions of the SDM measures were approved by IS, LK, and MH (“SDM-C Japanese (Patient)” (Fig. 1) and “SDM-C Japanese (Care staff)” in reference [13]).
Sample and setting
The data for secondary usage were collected from anonymized materials after the “Workshop to Learn Shared Decision-Making Support,” which was held by a government agency in Aichi Prefecture, Japan from September to November 2018. Medical (physicians, dentists, nurses, therapists, and pharmacists), long-term care (care managers and public healthcare nurses), and other (such as social workers) professionals attended the workshop as participants. The “care manager” plays a major role in care planning for care receiver under long-term care insurance in Japan. Therapists include physical, occupational, and speech therapists.
Workshop participants were recruited from local medical and long-term care professionals through recommendations of ten training sites (four hospitals, four municipalities, and two local medical associations) adopted by Aichi Prefecture. The workshop participants received a lecture on SDM and performed role-plays on cases presented in teams of three members each to learn SDM skills. In each team, one member played the role of a decision supporter, a different member played the role of a patient, and a third member played the role of an observer. We used several case vignettes such as decision support for people with cognitive impairment whose disease gradually progresses and activities of daily living gradually decline. As the case vignette, we used information from a single man with vascular dementia who lived alone and whose activities of daily living began to gradually decline. All role-playing teams worked on one patient model. Five decision-making vignettes had been prepared so that participants from various specialties could learn smoothly. Of these, One was a vignette in which a treatment decision had to be made at the time of outpatient examination, the second was a vignette in which the treatment decision had to be made in the hospital after a patient had a fall and had to be hospitalized on an emergency basis, the third was a vignette in which a decision regarding future care at home had to be made, the fourth was a vignette in which future medical treatment had to be made when a patient was entering a nursing home for a short period of time, and the fifth was a vignette in which a decision had to be made when a patient was receiving prescription drugs at a local family pharmacy. When the decision supporter was a physician, the Japanese SDM-Q-9 and SDM-Q-Doc were used to evaluate the treatment decision process. When the decision supporter was a HCP other than physicians, the SDM-C-patient and SDM-C-provider were used to evaluate the care decision process.
In these cases, professionals other than physicians acted as providers according to their profession, and other participants acted as patients and observers. After the role-play, the participants completed an appropriate SDM measure to evaluate the SDM process and discussed the possible improvements in patient–provider communications. After the workshop, the anonymized materials (role-play data using the SDM measures) were collected from ten training sites after the permission by the Aichi Prefecture, and the collected information was converted to electronic data by a person who was a staff member of the National Center for Geriatrics and Gerontology.
The descriptive data at the beginning of the SDM measures was converted into electronic data as it was. The Japanese versions of the SDM measures are six-point Likert-type scale questionnaires. Item scores were analyzed as “completely disagree,” which was scored as 0, and “completely agree,” which was scored as 5 points. We followed the development procedure of the original version and transformed the sum scale to range from 0 to 100 points. In this study, we used role-play data using SDM measures for those who played the patient and decision supporter roles for analysis.
The close fit model of covariance structure analysis was used to calculate the required sample size for the present study, based on the Japanese version of the SDM-Q-9 and SDM-Q-Doc [23]. The null hypothesis was the root mean square error of approximation (RMSEA) = 0, and the alternative hypothesis was RMSEA = 0.1. Based on the previous report on developing the Japanese version of SDM-Q-Doc [10], the degree of freedom, statistical power, and α error were set to 19, 0.8, and 0.05, respectively. Thus, the required sample size was 191 individuals.
Statistical analyses
The highest possible score was 45 points for the Japanese versions of the SDM-C-patient, SDM-C-provider, SDM-Q-9, and SDM-Q-Doc; scores were converted to those in a full score of 100 points before descriptive statistical analysis.
Confirmative factor analysis (CFA) of the Japanese version of the SDM-C-patient and SDM-C-provider were conducted. CFA was conducted with the assumption that SDM-C-patient and SDM-C-provider have a one-factor structure because the Japanese version of SDM-Q-9 [19]/Japanese version of SDM-Q-Doc [20] had the same one-factor structure as the original SDM-Q-9/SDM-Q-Doc. The goodness of fit of the model was evaluated using chi-squared test, comparative fit index (CFI), RMSEA, goodness-of-fit index (GFI), adjusted GFI (AGFI), and Akaikeʼs information criterion (ACI). In the CFA, residual correlations were added one at a time in the descending order of correlation, and the addition was stopped when the CFI of ≥ 0.95, RMSEA of ≤ 0.05, and GFI/AGFI of ≥ 0.95 were attained.
To confirm the reliabilities of the Japanese versions of the SDM-C-patient and SDM-C-provider, Cronbach’s α coefficient and McDonald’s ω coefficient were calculated to confirm internal consistencies.
Measurement invariance was investigated by testing each of the two pairs of four different SDM measures among those who attended the same lecture at the same workshop. To evaluate the measurement invariance of the measures for patient (SDM-C-patient vs. SDM-Q-9) and provider (SDM-C-provider vs. SDM-Q-Doc), we used the multigroup CFA. Metric and scalar invariances were confirmed in the same manner as that used for the patient and provider versions. Chen’s criteria [24], where ∆CFI of ≤ 0.010 and ∆RMSEA of ≤ 0.015 indicate the presence of invariance, were used to judge invariance.
IBM SPSS Statistics 27, IBM SPSS Amos Graphics 27 (IBM Corp., Armonk, NY, USA), and R 4.0.2. (A language and environment for statistical computing.). R Foundation for Statistical Computing, Vienna, Austria. URL: https://www.R-project.org/) were used for analysis.
Ethical considerations
This study involved the secondary usage of data provided after the workshops conducted at the training sites in Aichi Prefecture, and the analyzed data were entirely anonymized and included no information that could be used to identify specific individuals. Japan’s research ethics protocol, guidance on the ethical guidelines for medical and health research involving human subjects (revised March 23, 2021) [25], was published on April 16, 2021 [26]. To elaborate, in experiments and practical training conducted for academically known events such as health and hygiene training conducted exclusively for educational purposes, it is stated that if the obtained samples and data are not used for purposes other than educational ones, it may be judged that they do not fall under “research.”
This study is a secondary analysis of the information obtained from the training sessions conducted at the training sites in Aichi Prefecture, which is the main body responsible for conducting trainings.
At the time of the workshop, the following explanation was provided verbally and via slide presentation: “The training sites provide workshop information, which does not contain any personal identifiable information collected at the workshop, to another institution for training feedback and analysis.” For this study, the training sites collected information regarding the workshop and provided it to our researchers. Our researchers received the information that an individual could not be identified and the study was conducted using that information. In the third item, “scope of application,” of the ethical guideline for medical and health research involving human subjects (revised March 23, 2021) [25], information that has already been anonymized (limited to that by which a specific individual cannot be identified and a correspondence table has not been created) is excluded. Judgments outside the scope of this guideline were confirmed by several Japanese researchers who have received ethical education.