Table 3 Risk of bias assessed by NOS assessment tool
| Author/Year | Design | Selection | Comparability | Outcome /Exposure | NOS score |
|---|---|---|---|---|---|
| Pascale, 2017 | case-control study | ⁕⁕⁕ | ⁕⁕ | ⁕⁕ | 7 |
| Venugopalan, 2017 | cohort study | ⁕⁕⁕⁕ | ⁕⁕ | ⁕ | 7 |
| Cancelli, 2018 | cohort study | ⁕⁕⁕⁕ | ⁕⁕ | ⁕ | 7 |