Table 2.
The quality assessment of included studies.
| Study (cohort) | Representativeness of exposed cohort | Selection of non-exposed cohort | Ascertainment of exposure | Outcome not present before study | Comparability | Assessment of outcome | Follow-up long enough* | Adequacy of follow up |
Quality score |
|---|---|---|---|---|---|---|---|---|---|
| Sung et al. (19) |
|
|
|
|
|
|
|
|
9 |
| Li et al. (21) |
|
|
|
|
|
|
|
|
9 |
| Study (case-control) | Case definition | Representativeness of the cases | Selection of controls | Definition of controls | Comparability | Ascertainment of exposure | Same method of ascertainment | Non-response rate |
Quality score |
| Rugbjerg et al. (20) |
|
|
|
|
|
|
|
|
7 |
| Bacelis et al. (26) |
|
|
|
|
|
|
|
|
8 |
*
Median follow-up of more than 5 year or maximum follow-up of more than 10 years was assigned a star.