Table 2.
The Newcastle-Ottawa Scale (NOS) used for evaluating the risk of bias within Studies
| First Author, Date | Quality evaluation |
Representativeness of exposed cohort |
Selection of non- exposed cohort | Ascertainment of exposure |
Outcome not present before study |
Comparability | Assessment of outcome |
follow-up long enough |
Adequacy of Follow Up |
|---|---|---|---|---|---|---|---|---|---|
|
Jia (2013) |
8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
|
Supic (2018) |
8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
| Zheng(2016) | 7 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 1 |
|
Jia (2014) |
8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
|
Li (2009) |
8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
| Kawakita(2014) | 8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
|
Maruyama (2018) |
7 | 1 | 0 | 1 | 0 | 2 | 1 | 1 | 1 |
|
Xie (2016) |
8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
| Berania(2017) | 8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
|
Jia (2015) |
7 | 1 | 1 | 1 | 0 | 2 | 1 | 0 | 1 |
|
W. Chen (2019) |
8 | 1 | 1 | 1 | 0 | 2 | 1 | 1 | 1 |
|
S. Chen (2019) |
7 | 1 | 1 | 1 | 0 | 2 | 1 | 0 | 1 |