Table 2 Study quality of included cohort studies based on the Newcastle–Ottawa scale
Authors | 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 | Comparability of cohorts on the basis of the design or analysisa | Assessment of outcome | Was follow-up long enough for outcomes to occur | Adequacy of follow-up of cohorts | Scores |
|---|---|---|---|---|---|---|---|---|---|
Qian et al. [20] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Huang et al. [22] | ★ | ★ | ★ | ★ | ★★ | ★ | 7 | ||
Tian et al. [23] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Yang et al. [24] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Wen et al. [25] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Zhang et al. [26] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Lu et al. [27] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Zeng et al. [29] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Cao et al. [30] | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
Huang et al. [31] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Xu et al. [32] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Ma et al. [33] | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
Liu et al. [34] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Rao et al. [35] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Yao et al. [36] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Li et al. [37] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Cedric Barrey et al. [38] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Zhang et al. [39] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Liu et al. [40] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 7 | |
Ji et al. [42] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Song et al. [43] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Zhang et al. [44] | ★ | ★ | ★ | ★★ | ★ | ★ | 7 | ||
Li et al. [46] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Rong et al. [47] | ★ | ★ | ★ | ★ | ★ | ★ | 6 | ||
Guan et al. [48] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Guan et al. [49] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |
Zhao et al. [50] | ★ | ★ | ★ | ★ | ★ | ★ | ★ | ★ | 8 |