Table 4.
Quality assessment of included studies using Newcastle–Ottawa Scale
| Author | Year | Representativeness of exposed cohort | Selection of non-exposed cohort | Ascertainment of exposure | Outcome of interest not present at beginning of study | Comparability of cohort | Assessment of outcome | Follow-up | Adequacy of follow-up |
|---|---|---|---|---|---|---|---|---|---|
| Kalaignan P et al | 2018 | * | – | * | * | * | * | – | – |
| Aimaijang Y et al | 2015 | ** | * | ** | * | ** | * | * | * |
| Schweyen R et al | 2016 | ** | * | ** | * | ** | * | * | - |
| Fierz J et al | 2013 | * | * | ** | * | ** | * | ** | * |
| Sato et al | 2019 | * | * | ** | * | ** | * | ** | ** |
| Karayazgan Saracoglu BK et al | 2017 | ** | * | ** | * | ** | * | ** | ** |