Table 2.
Item Characteristics of the Japanese Version of SDM-Q-9 (N = 131).
| Minimum value | Maximum value | Mean (median) | SD | Cronbach’s α if item deleted | I-T correlation | Factor loading | |
|---|---|---|---|---|---|---|---|
| SDM1．My doctor made clear that a decision needs to be made. | 0 | 11.11 | 9.79 (11.11) | 1.945 | 0.901 | 0.755 | 0.618 |
| SDM2．My doctor wanted to know exactly how I want to be involved in making the decision. | 0 | 11.11 | 10.08 (11.11) | 1.771 | 0.908 | 0.649 | 0.449 |
| SDM3．My doctor told me that there are different options for treating my medical condition. | 0 | 11.11 | 9.52 (11.11) | 2.343 | 0.898 | 0.794 | 0.747 |
| SDM4. My doctor precisely explained the advantages and disadvantages of the treatment options. | 0 | 11.11 | 9.19 (11.11) | 2.655 | 0.897 | 0.816 | 0.780 |
| SDM5. My doctor helped me understand all the information. | 6.667 | 11.11 | 10.14 (11.11) | 1.325 | 0.914 | 0.571 | 0.312 |
| SDM6．My doctor asked me which treatment option I prefer. | 0 | 11.11 | 9.94 (11.11) | 1.936 | 0.907 | 0.670 | 0.471 |
| SDM7．My doctor and I thoroughly weighed the different treatment options. | 0 | 11.11 | 8.77 (8.89) | 2.774 | 0.902 | 0.765 | 0.658 |
| SDM8．My doctor and I selected a treatment option together. | 0 | 11.11 | 9.75 (11.11) | 1.979 | 0.901 | 0.756 | 0.569 |
| SDM9．My doctor and I reached an agreement on how to proceed. | 0 | 11.11 | 10.26 (11.11) | 1.594 | 0.910 | 0.619 | 0.368 |