Table 1. NOS for risk of bias assessment of included studies.
| Study | Selection | Comparability | Outcome | Total | |||||
|---|---|---|---|---|---|---|---|---|---|
| Adequacy of case definition | Number of case | Representativeness of the cases | Ascertainment of exposure | Ascertainment of detection method | Ascertainment of cut-off | Assessment of outcome | Adequate follow-up | ||
| Jiang, X.M. [12] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Zhang, E. [13] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Dou, C.Q [14] | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 6 |
| Lv, L. [17] | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
| Zhou, B.G. [18] | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | 6 |
| Zhang, X.F. [19] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Zhu, H.Q [15] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| Deng, L. [16] | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
| He, X. [20] | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
NOS = Newcastle-Ottawa Scale.