Table 1 . Evaluation of content validity index (CVI) for questions of 12-PSS .
| Question | Relevance | Simplicity | Clarity | Ambiguity |
| 1 | 100% | 100% | 100% | 100% |
| 2 | 100% | 100% | 100% | 100% |
| 3 | 100% | 100% | 83.33% | 83.33% |
| 4 | 83.33% | 83.33% | 83.33% | 83.33% |
| 5 | 100% | 100% | 100% | 83.33% |
| 6 | 100% | 100% | 100%v | 100% |
| 7 | 100% | 100% | 100% | 100% |
| 8 | 100% | 100% | 100% | 100% |
| 9 | 100% | 100% | 100% | 100% |
| 10 | 100% | 100% | 100% | 100% |
| 11 | 100% | 100% | 100% | 100% |
| 12 | 100% | 100% | 100% | 100% |