Table 5 Risk of bias assessment of retrospective studies
| Â | Adequacy of case definition | Case number | Representativeness of the cases | As of interventions | As of detection method | As of cutoff | As of outcome | Adequacy of follow up | NOS score |
|---|---|---|---|---|---|---|---|---|---|
Huang, 2019 [23] | Low risk | High risk | High risk | Low risk | Low risk | Low risk | Low risk | Low risk | 7 |
Jin, 2014 [21] | Low risk | High risk | High risk | Low risk | High risk | Low risk | Unclear risk | Low risk | 5 |
Liu, 2016 [20] | Unclear risk | High risk | Low risk | Low risk | Low risk | Unclear risk | High risk | High risk | 5 |
Liu, 2016 [18] | Low risk | Low risk | High risk | Low risk | Low risk | Low risk | Low risk | Low risk | 8 |
Sun, 2016 [19] | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | 8 |
Wang, 2018 [16] | Low risk | High risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | 8 |
Wang, 2017 [13] | Low risk | High risk | Low risk | Unclear risk | Low risk | Low risk | Low risk | Low risk | 7 |
Wang, 2019 [12] | Low risk | High risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | 8 |
Wang, 2019 [11] | Low risk | Low risk | Unclear risk | Low risk | Unclear risk | Low risk | Low risk | Low risk | 7 |
Xiao, 2019 [14] | Low risk | High risk | Low risk | High risk | Low risk | Unclear risk | High risk | Low risk | 5 |
Ye, 2017 [17] | Unclear risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | 8 |
Qi, 2019 [22] | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | 7 |