Table 3 Quality assessment of the included retrospective and prospective studies
Study ID | Selection | Comparability | Outcome | Total score | |||
|---|---|---|---|---|---|---|---|
Representativeness of exposed cohort | Selection of non-exposed cohort | Ascertainment of exposure | Comparability of cohorts on the basis of the design or analysis | Assessment of outcome | Adequacy of follow up of cohorts | ||
Arora 2009 [16] | 0 | 1 | 1 | 2 | 1 | 1 | 6 |
Chan 2014 [17] | 0 | 1 | 1 | 2 | 1 | 1 | 6 |
Egol 2010 [18] | 1 | 1 | 1 | 2 | 1 | 1 | 7 |
Hung 2015 [4] | 1 | 1 | 1 | 2 | 1 | 1 | 7 |
Lutz 2014 [19] | 0 | 1 | 1 | 1 | 0 | 1 | 4 |
Zengin 2019 [22] | 0 | 1 | 1 | 2 | 1 | 1 | 6 |