Table 2.
Quality assessment of studies included in this meta-analysis by Newcastle-Ottawa Scale
| Study | Selection | Comparability | Exposure | Quality evaluation | |||||
|---|---|---|---|---|---|---|---|---|---|
| Cases definition | Cases representativeness | Control selection | Controls definition | Comparability | Ascertainment of exposure | Same ascertainment | Non-response rate | ||
| Shaw CK 1993 [33] | a | b | a | a | b | b | a | a | 7 |
| Chumnumnawin M 2008 [34] | a | a | b | a | b | b | a | a | 7 |
| El-Heis MA 2013 [35] | a | b | b | a | b | b | a | a | 6 |
| Zhou R 2013 [36] | a | a | a | a | a + b | b | a | a | 8 |
| Daisuke A 2015 [37] | a | a | b | a | b | b | a | a | 7 |
| Saei GNM 2015 [38] | a | a | b | a | b | b | a | a | 7 |
| Liu D 2016 [39] | a | a | a | a | a + b | b | a | a | 9 |
| Neglia C 2016 [40] | a | b | c | a | b | b | a | a | 6 |
| Dana H 2017 [41] | a | a | a | a | b | b | a | a | 8 |
| Heidari B 2017 [42] | a | a | a | a | b | b | a | a | 8 |
| Lee SH 2017 [43] | a | a | a | a | b | b | a | a | 8 |
| Lin HH 2018 [44] | a | b | b | a | b | b | a | a | 6 |
| Yoo JE 2018 [45] | a | a | b | a | a + b | b | a | a | 8 |
| Wang Y 2019 [46] | a | a | b | a | b | b | a | a | 7 |