Table 3.
Quality assessment of the included investigations
| Authors and year | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | Total score |
| Baez et al43 | 2 | 2 | 2 | 1 | 1 | 2 | 2 | 0 | NA | NA | NA | NA | 12/16 |
| Barchek et al44 | 2 | 2 | 2 | 2 | 1 | 2 | 2 | 1 | NA | NA | NA | NA | 14/16 |
| Bell et al35 | 2 | 2 | 2 | 2 | 0 | 2 | 2 | 2 | 2 | 1 | 1 | 2 | 20/24 |
| Davis-Wilson et al45 | 2 | 2 | 1 | 2 | 1 | 2 | 1 | 2 | NA | NA | NA | NA | 13/16 |
| Ezzat et al36 | 2 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 2 | 1 | 2 | 2 | 22/24 |
| Kuenze et al37 | 1 | 2 | 2 | 2 | 0 | 2 | 2 | 2 | 2 | 2 | 2 | 1 | 20/24 |
| Kuenze et al38 | 2 | 2 | 1 | 2 | 0 | 2 | 1 | 1 | 2 | 1 | 2 | 2 | 18/24 |
| Kuenze et al46 | 2 | 2 | 2 | 2 | 0 | 2 | 2 | 1 | NA | NA | NA | NA | 13/16 |
| Kuenze et al42 | 2 | 2 | 2 | 1 | 0 | 2 | 1 | 1 | NA | NA | NA | NA | 11/16 |
| Lisee et al39 | 2 | 1 | 2 | 1 | 1 | 2 | 1 | 1 | 2 | 2 | 2 | 1 | 18/24 |
| Toomy et al40 | 2 | 1 | 2 | 2 | 0 | 2 | 1 | 1 | 2 | 1 | 1 | 2 | 17/24 |
| Triplett and Kuenze41 | 2 | 2 | 2 | 1 | 1 | 1 | 0 | 1 | 2 | 2 | 1 | 1 | 16/24 |
All items are scored 0 (not reported), 1 (reported but inadequate) and 2 (reported and adequate). The maximum score for non-comparative studies is 16 and the maximum score for comparative studies is 24. 1, a clearly stated aim; 2, inclusion of consecutive patients; 3, prospective collection of data; 4, endpoints appropriate to the aim of the study; 5, unbiased assessment of the study endpoint; 6, follow-up period appropriate to the aim of the study; 7, loss to follow-up less than 5%; 8, prospective calculation of the study size; 9, an adequate control group; 10, contemporary groups; 11, baseline equivalence of groups; 12, adequate statistical analyses.
NA, not applicable.