Quality assessment of included studies
| Included trials | Trial described as randomised (1=yes, 0=no) | Randomised method described and appropriate (1=yes, 0=no) | Allocation concealment described* (1=yes, 0=no) | Allocation concealment described and appropriate (1=yes, 0=no) | Trial described as double blind (1=yes, 0=no) | Double blind method described and appropriate (1=yes, 0=no) | Withdrawals and dropouts described (1=yes, 0=no) | Jadad score† |
|---|---|---|---|---|---|---|---|---|
| Merten et al 19 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 4 |
| Ozcan et al 50 | 1 | 0 | 0 | 0 | 0 | 0 | 1 | 2 |
| Masuda et al 33 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 4 |
| REMEDIAL et al 20 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 5 |
| Adolph et al 7 | 1 | 1 | 0 | 0 | 1 | 0 | 1 | 5 |
| Brar et al 8 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 5 |
| Maioli et al 9 | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 4 |
| Tamura et al 23 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 4 |
| Vasheghani et al 10 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 4 |
| Castini et al 12 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 3 |
| Vasheghani et al 11 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 4 |
| Motohiro et al 24 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 4 |
| PREVENT et al 13 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 4 |
| Ueda et al 18 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 3 |
| Klima et al 21 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 3 |
| Gomes et al 15 | 1 | 0 | 1 | 1 | 0 | 0 | 0 | 3 |
| Hafiz et al 14 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 4 |
| Kristeller et al 17 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 5 |
| Boucek et al 16 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | 6 |
| Kooiman et al 22 | 1 | 1 | 0 | 0 | 0 | 0 | 1 | 4 |
*One point is allocated according to the Jadad score if the randomisation method of the trial is described and appropriate.
†Assessment of included trials: low quality, 1–3; high quality, 4–7.