Levels of evidence and quality assessment ratings of health service accreditation literature
| Frequency of quality assessment ratings | |||||
|---|---|---|---|---|---|
| Study design groups | Levels of evidence | Number of studies | 1 | 2 | 3 |
| Intervention group | 1 | 1 | 0 | 0 | 1 |
| 2 | 1 | 0 | 1 | 0 | |
| 3a | 1 | 0 | 1 | 0 | |
| 3b | 7 | 2 | 3 | 2 | |
| 3c | 3 | 2 | 1 | 0 | |
| 4 | 8 | 3 | 3 | 2 | |
| Aetiology group | 1 | 0 | 0 | 0 | 0 |
| 2 | 1 | 0 | 0 | 1 | |
| 3a | 0 | 0 | 0 | 0 | |
| 3b | 19 | 0 | 3 | 16 | |
| 3c | 4 | 1 | 3 | 0 | |
| 4 | 48 | 15 | 21 | 12 | |
| 5 | 29 | 14 | 7 | 8 | |
| Totals | 122 | 37 | 43 | 42 | |