Table 2.
Quality evaluation of retrospective clinical studies
| Included study | Study type | Rated items |
Quality score | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Selection (4) |
Comparability (2) |
Outcomes (3) |
||||||||
| ① | ② | ③ | ④ | ⑤ | ⑥ | ⑦ | ⑧ | |||
| Liu et al. [20] (2018) | Retrospective | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 (Hi-Q) |
| Hsu et al. [13] (2013) | Retrospective | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 6 (Hi-Q) |
| Yang et al. [36] (2015) | Retrospective | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 7 (Hi-Q) |
| Li et al. [17] (2018) | Retrospective | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 (Hi-Q) |
| Zhao et al. [38] (2012) | Retrospective | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 7 (Hi-Q) |
| Choi et al. [7] (2016) | Retrospective | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 (Hi-Q) |
| Kim et al. [16] (2007) | Retrospective | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 (Hi-Q) |
| Wang et al. [33] (2013) | Retrospective | 1 | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 7 (Hi-Q) |
① : case definition, ② : representativenes, ③ : control selection, ④ : control definition, ⑤ : A/B : the comparability of cases and controls in design and statistical analysis, ⑥ : ascertainment of exposure, ⑦ : same method of ascertainment for cases and controls, ⑧ : non-response rate