Table 3.
Methodological quality assessment of cohort studies: the Newcastle-Ottawa Scale
| First author (year) | Representativeness of the exposed cohort | Selection of the non-exposed cohort | Selection of exposure | Outcome of interest was Ffter start of study | Control for important factor | Assessment of outcome | Sufficient follow-up | Adequacy of follow-up of cohorts |
|---|---|---|---|---|---|---|---|---|
| Zheng et al. (2018) | ★ | ✰ | ★ | ★ | ✰✰ | ✰ | ★ | ★ |
| Huo et al. (2017) | ★ | ★ | ★ | ★ | ✰✰ | ✰ | ★ | ★ |
| Dong et al. (2017) | ★ | ★ | ★ | ★ | ✰★ | ✰ | ★ | ★ |
| Chang et al. (2015) | ★ | ★ | ★ | ★ | ✰✰ | ✰ | ★ | ★ |
| Zhao et al. (2009) | ★ | ★ | ★ | ★ | ✰★ | ✰ | ★ | ★ |
| Zhang et al. (2013) | ★ | ★ | ★ | ★ | ✰★ | ✰ | ★ | ★ |
| Xu et al. (2013) | ★ | ★ | ★ | ★ | ✰★ | ✰ | ★ | ★ |
★
Article is given a point for meeting the corresponding criterion.
✰
Indicates no point.