Table S1.
Methodological quality of the included studies according to the Newcastle-Ottawa scale
| Reference | Year | Ethnicity/location | Adequacy of case definition |
Representative ness of the cases |
Selection of controls |
Definition of controls |
Comparability cases/controls |
Ascertainment of exposure |
Same method of ascertainment |
Non-response rate |
Total |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Chang | 2011 | Chinese | * | * | * | NA | * | * | * | NA | 7 |
| Miyake | 2012 | Japanese | * | * | * | NA | * | * | * | * | 8 |
| Chang | 2015 | Chinese | * | * | * | NA | * | * | * | NA | 7 |
| Cui | 2018 | Chinese | * | * | * | NA | * | * | * | * | 8 |
| Tian | 2012 | Chinese | * | * | * | NA | * | * | * | NA | 7 |
| Satake | 2011 | Japanese | NA | NA | * | * | * | * | * | NA | 6 |
| Tan | 2010 | Chinese | NA | NA | * | * | * | * | * | NA | 6 |
| Simón-Sánchez | 2011 | the Netherlands | * | * | * | * | * | * | NA | * | 8 |
| Spencer | 2011 | UK | NA | NA | * | NA | * | * | * | * | 6 |
| Xie | 2011 | Chinese | NA | NA | * | * | * | * | NA | * | 6 |
| Chen | 2014 | Chinese | * | * | * | NA | * | * | * | * | 8 |
Notes: This table identifies high quality choices with “an asterisk.” A study can be awarded a maximum of one star for each numbered item within the Selection and Exposure categories. A maximum of two stars can be given for Comparability.
Abbreviations: *, Yes; NA, not applicable.