Meta-regression based on quality assessment tools (NOS)
| Subgroups | Type of questionnaires | Number of studies | Point estimate | Lower | Upper | I2 |
| Quality assessment tool (NOS) | High | 60 | 57.32 | 52.14 | 64.37 | 99.44% |
| Medium | 64 | 41.67 | 36.47 | 48.74 | 95.87% | |
| Low | 23 | 49.87 | 43.54 | 59.17 | 98.65% |
NOS, Newcastle–Ottawa Scale.