Table 2 Quality assessment for each included cohort study
Item | Ismail M 2009 [10] | Sinha R 2008 [9] | Sunamak 2018 [12] | Symeonidis 2013 | Yildirim D 2017 [14] |
|---|---|---|---|---|---|
Item 1: The selection of the study groups | |||||
Representativeness of the exposed cohort | ☆ | ☆ | ☆ | ☆ | ☆ |
Selection of the non exposed cohort | ☆ | ☆ | ☆ | ☆ | ☆ |
Ascertainment of exposure | ☆ | ☆ | ☆ | ☆ | ☆ |
Demonstration that outcome of interest was not present at start of study | ☆ | ☆ | ☆ | ☆ | ☆ |
Item 2: The comparability of the groups | ☆☆ | ☆☆ | ☆☆ | ☆☆ | ☆☆ |
Item 3: The ascertainment of either the exposure or outcome of interest for cohort studies | |||||
Assessment of outcome | ☆ | ☆ | ☆ | ☆ | ☆ |
follow-up long enough for outcomes to occur | ☆ | ☆ | ☆ | ☆ | ☆ |
Adequacy of follow up of cohorts | ☆ | ☆ | ☆ | ☆ | |