Table 2 Quality assessment of non-randomized comparative studies
Study | Selection | Comparability | Outcome | Total |
|---|---|---|---|---|
Alvin et al. [20] | 4 | 2 | 3 | 9 |
Cho et al. [9] | 3 | 1 | 3 | 7 |
Dunn et al. [26] | 4 | 1 | 3 | 8 |
Forster et al. [18] | 4 | 2 | 3 | 9 |
Korinth et al. [23] | 4 | 1 | 3 | 8 |
Lin et al. [10] | 4 | 1 | 3 | 8 |
Mansfield et al. [27] | 3 | 1 | 3 | 7 |
Mok et al. [17] | 4 | 1 | 2 | 7 |
Scholz et al. [19] | 3 | 0 | 3 | 7 |
Selvanathan et al. [21] | 3 | 1 | 3 | 7 |
Tumialan et al. [22] | 3 | 2 | 3 | 8 |
Witiw et al. [16] | 4 | 1 | 2 | 7 |