Table 2 Risk of bias assessment
| Domain | Potential bias | Studies |
|---|---|---|
| 1. Study participation |
Yes Partly No Unsure |
Ford et al., Bae et al. Ye et al. Chen et al., Xie et al., Johnstone et al., Ryan et al., Gouliouris et al., Kramer et al. None |
| 2. Study attrition |
Yes Partly No Unsure |
None Chen et al. Ford et al., Xie et al., Ye et al., Johnstone et al., Ryan et al., Gouliouris et al., Kramer et al., Bae et al. None |
| 3. Prognostic factor measurement |
Yes Partly No Unsure |
None None Chen et al., Ford et al., Xie et al., Ye et al., Johnstone et al., Ryan et al., Gouliouris et al., Kramer et al., Bae et al. None |
| 4. Outcome measurement |
Yes Partly No Unsure |
None None Chen et al., Ford et al., Xie et al., Ye et al., Johnstone et al., Ryan et al., Gouliouris et al., Kramer et al., Bae et al. None |
| 5. Confounding measurement and account |
Yes Partly No Unsure |
Ford et al., Bae et al. Ye et al. Chen et al., Xie et al., Johnstone et al., Ryan et al., Gouliouris et al., Kramer et al. None |
| 6. Analysis |
Yes Partly No Unsure |
None None Chen et al., Ford et al., Xie et al., Ye et al., Johnstone et al., Ryan et al., Gouliouris et al., Kramer et al., Bae et al. None |