Table 2 Quality assessment of included studies according to the Newcastle-Ottawa Scale
Item/Study | Adequate definition of cases | Representativeness of cases | Selection of control subjects | Definition of control subjects | Control for important factor | Exposure assessment | Same method of ascertainment for all subjects | Non-response rate | Total |
|---|---|---|---|---|---|---|---|---|---|
Hu XJ, 2019 [18] | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 6 |
Jin SY, 2019 [19] | 1 | 0 | 0 | 1 | 2 | 1 | 1 | 1 | 7 |
Coto E, 2019 [20] | 1 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 7 |
Seidi A, 2018 [21] | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 6 |
Luo JY, 2017 [22] | 1 | 0 | 0 | 1 | 2 | 1 | 1 | 1 | 7 |
Lai HM, 2015 [23] | 1 | 0 | 1 | 1 | 2 | 1 | 1 | 1 | 8 |
Lai H, 2015 [24] | 1 | 0 | 1 | 1 | 2 | 1 | 1 | 1 | 8 |
Arslan S, 2015 [25] | 1 | 0 | 0 | 1 | 2 | 1 | 1 | 1 | 7 |
Yang YN, 2015 [26] | 1 | 0 | 1 | 1 | 2 | 1 | 1 | 1 | 8 |
Mishra A, 2013 [27] | 1 | 0 | 0 | 1 | 2 | 1 | 1 | 1 | 7 |
Stegger JG, 2013 [28] | 1 | 1 | 1 | 1 | 2 | 1 | 1 | 1 | 9 |
Mishra A, 2013 [27] | 1 | 1 | 0 | 1 | 2 | 1 | 1 | 1 | 8 |
Xie FY, 2008 [15] | 1 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 6 |