Table 2 Risk of bias summary: review of authors’ judgments about the risk of bias in each study included
References | Representativeness of the cases | Selection of control | Ascertainment of exposure | Interest outcome not present at start cohorts of study | Comparability of cohorts | Control for any additional factors | Assessment of outcome | Enough follow up | Adequacy of follow up |
|---|---|---|---|---|---|---|---|---|---|
Baumfeld et al. [9] | – | – | – | – | + | + | + | + | – |
Kong et al. [10] | – | – | – | – | + | + | + | + | – |
Lopes et al. [11] | – | – | – | – | – | + | + | + | – |
Saygi et al. [12] | – | – | – | – | + | + | + | + | – |
Srinivas et al. [13] | – | – | – | – | + | + | + | – | – |
Uzumcugil et al. [14] | – | – | – | – | + | + | + | + | – |