Table 1.
Items of the psychometric methods
| 1. Item and dimension generation | |
| The item generation phase should include all important elements of patient’s preferences by reviewing the existing questionnaires, literature, and opinions from experts and patient focus groups. The authors should describe the generation of initial items, including literature review,26 the Delphi survey,27 and consensus meetings,28 etc. | ⎕ Yes |
| ⎕ No | |
| ⎕ Uncertain | |
| ⎕ Not applicable | |
| 2. Pretest and pilot testing | |
| The authors should state that they pretested the items of questionnaires. The process of pretest and pilot testing is for revision of the questionnaire into the final validated version by using the response from the protest group. Items with ambiguous meanings can be eliminated to maximize the reliability and validity of the questionnaire. | ⎕ Yes |
| ⎕ No | |
| ⎕ Uncertain | |
| ⎕ Not applicable | |
| 3. Validity testing | |
| Content validity. It is usually reported in questionnaires judged by the panel after literature reviews and focus group interviews. During the testing phase, patients are asked to review the items in the questionnaire for content validity on patient’s values and preferences before it is administered to study participants. | ⎕ Yes |
| ⎕ No | |
| ⎕ Uncertain | |
| Construct validity. Because there is no standard for measuring patient’s satisfaction, researchers usually compare their questionnaire with other validated instruments or other related questions for this correlation. Discriminant validity requires that the construct should not show correlation with dissimilar variables. | ⎕ Not applicable |
| 4. Reliability testing | |
| The authors should state that they tested the reliability. | ⎕ Yes |
| Internal consistency. Cronbach’s α should be reported, the value should be 0.7–0.9, as a value above 0.9 may indicate that the questionnaire is too narrow in scope. | ⎕ No |
| ⎕ Uncertain | |
| Test-retest reliability. The minimum value of the correlation coefficient should be 0.7. | ⎕ Not applicable |
| Intrarater and interrater agreements. Intrarater agreement is the agreement between observations made by the same rater on two different occasions. | |
| 5. Feasibility/acceptability | |
| Time to complete. The authors should provide the time to complete the questionnaires. | ⎕ Yes |
| ⎕ No | |
| Response rates. The authors should provide the response rates of the questionnaires. A response rate of 50% is considered adequate for analysis.29 | ⎕ Uncertain |
| ⎕ Not applicable |