Table 2 Study quality evaluation via the Newcastle–Ottawa Scale
Study | Representativeness of the exposed cohort | Selection of the non-exposed cohort | Ascertainment of exposure | Outcome not present at baseline | Control for age and sex | Control for other confounding factors | Assessment of outcome | Enough long follow-up duration | Adequacy of follow-up of cohorts | Total |
|---|---|---|---|---|---|---|---|---|---|---|
Meding 2003 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 |
Bolognesi 2008 | 1 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 7 |
Moon 2008 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Wang 2013 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Adams 2013 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Zhao 2014 | 0 | 1 | 1 | 1 | 1 | 0 | 1 | 1 | 1 | 7 |
Kang 2015 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Song 2016 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 7 |
Martinez 2017 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Dai 2020 | 1 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 7 |
Gu 2020 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 1 | 6 |
Lee 2021 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 8 |
Gao 2023 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 9 |