| Causes Authors | Organizational | Patient-related |
| Cho [7] South Korea 2018 | 6.4% | 93.6% |
| Turunen [5] Finland 2018 | 56.1 | 34.2 |
| Mesmar [8] Jordany 2010 | 30.4% | 31.4% |
| Our Study | 28.1% | 51.2% |